<PAGE>
 
================================================================================

                                   FORM 10-Q

                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C.  20549

                            ______________________

         [X]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                        SECURITIES EXCHANGE ACT OF 1934

                 For the quarterly period ended March 31, 1999

                                      OR

         [_]  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                        SECURITIES EXCHANGE ACT OF 1934

                 For the transition period from _____ to _____

                         Commission file number 1-5259

                             ____________________

                             PITT-DES MOINES, INC.
            (Exact name of registrant as specified in its charter)

        Commonwealth of Pennsylvania                         25-0729430
       (State or other jurisdiction of                    (I.R.S. Employer
       incorporation or organization)                     Identification No.)

     1450 Lake Robbins Drive, Suite 400, The Woodlands, TX          77380
           (Address of Principal Executive Offices)               (Zip Code)

                                (281) 765-4600
             (Registrant's Telephone Number, including Area Code)
                             ____________________

     Indicate by check whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.
Yes  [X]   No  [_]

     On March 31, 1999,  7,263,702 shares of Common Stock were outstanding.

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<PAGE>
 
                               TABLE OF CONTENTS

                                                                            PAGE

Part I - Financial Information

         Item 1. Financial statements                                          3
 
         Item 2. Management's discussion and analysis of
                 financial condition and results of operations                11
 
         Item 3. Quantitative and qualitative disclosures about market risk   15
 

Part II - Other Information

         Item 1. Legal proceedings                                            16

         Item 6. Exhibits and reports on Form 8-K                             16


Signatures                                                                    17


Exhibit Index                                                                 18

                                      -2-
<PAGE>
 
                        Part I.  Financial Information

Item 1.  Financial Statements

                             PITT-DES MOINES, INC.
                       Consolidated Statements of Income
                                  (Unaudited)
 
                                               For the three months ended
                                                          March 31,
                                                  ----------------------
(in thousands, except per share amounts)             1999         1998
                                                  ---------    ---------
Earned revenue                                    $ 142,846    $ 123,370
Cost of earned revenue                             (122,314)    (104,295)
                                                  ---------    ---------
Gross profit from operations                         20,532       19,075
 
Selling, general and administrative expenses        (12,050)     (11,552)
                                                  ---------    ---------
 Income from operations                               8,482        7,523
 
Other income/(expense):
 Interest income                                        177          139
 Interest expense                                      (702)        (264)
 Gain on sale of assets                                 950           18
 Miscellaneous, net                                    (196)        (597)
                                                  ---------    ---------
                                                        229         (704)
                                                  ---------    ---------
 Income before income taxes                           8,711        6,819
 Income taxes                                        (3,414)      (2,651)
                                                  ---------    ---------
 Net income                                       $   5,297    $   4,168
                                                  =========    =========
Per common share:
 Earnings per share                                   $0.75        $0.59
                                                  =========    =========
 Earnings per share - assuming dilution               $0.71        $0.58
                                                  =========    =========
 
Cash dividend                                         $0.17        $0.15
                                                  =========    =========
 
Shares used to calculate:  (in thousands)
 
 Earnings per share                                   7,106        7,032
                                                  =========    =========
 
 Earnings per share - assuming dilution               7,451        7,198
                                                  =========    =========
 
 
CONSOLIDATED RETAINED EARNINGS
Balance at the beginning of year                  $ 126,082    $ 110,096
 Net income                                           5,297        4,168
 Dividends paid                                      (1,232)      (1,057)
 Other                                                  (23)         144
                                                  ---------    ---------
Balance at end of period                          $ 130,124    $ 113,351
                                                  =========    =========

See Notes to Consolidated Financial Statements.

                                      -3-
<PAGE>
 
Item 1.  Financial Statements (Continued)


                             PITT-DES MOINES, INC.
                Consolidated Statements of Financial Condition

 
                                                    March 31,      December 31,
                                                       1999            1998
                                                     --------        --------
(in thousands)                                      (Unaudited)
 
Assets
 
Current Assets
 
     Cash and cash equivalents                       $ 17,440        $  8,447
     Accounts receivable including retentions
     (less allowances:  1999-$840; 1998-$793)         110,861         103,998
     Inventories                                       25,150          31,118
     Costs and estimated profits in excess
      of billings                                      60,660          63,700
     Deferred income taxes                              5,844           5,876
     Prepaid expenses                                   3,619           1,205
                                                     --------        --------
          Total Current Assets                        223,574         214,344
 
 
 
Other Assets                                           10,826          10,454
 
Goodwill                                                7,364           6,588
 
Property, Plant and Equipment
     Land                                               7,674           9,637
     Buildings                                         46,214          44,091
     Machinery and equipment                           77,355          75,712
                                                     --------        --------
                                                      131,243         129,440
Allowances for depreciation                           (73,449)        (71,443)
                                                     --------        --------
     Net Property, Plant and Equipment                 57,794          57,997
                                                     --------        --------
                                                     $299,558        $289,383
                                                     ========        ========


See Notes to Consolidated Financial Statements.

                                      -4-
<PAGE>
 
Item 1.  Financial Statements (Continued)

                             PITT-DES MOINES, INC.
                Consolidated Statements of Financial Condition
<TABLE>
<CAPTION>
                                                             March 31,    December 31,
                                                               1999           1998
                                                            -----------   -------------
(in thousands)                                              (Unaudited)
<S>                                                         <C>           <C>
 
Liabilities
 
Current Liabilities
     Accounts payable                                         $ 35,749        $ 52,777
     Accrued compensation, related taxes and benefits           12,801          14,200
     Other accrued expenses                                      3,215           3,655
     Billings in excess of costs and estimated profits          20,650          14,774
     Income taxes                                                6,202           4,640
     Casualty and liability insurance                            7,250           5,784
                                                              --------        --------
     Total Current Liabilities                                  85,867          95,830
 
Revolving Credit Facility                                       52,000          35,000
 
Deferred Income Taxes                                            6,911           6,937
 
Minority Interest                                                  827           2,362
 
Contingencies and Commitments
 
Stockholders' Equity
 
     Preferred stock - par value $.01 per share;
      authorized 3,000,000 shares; issued - none
     Common stock - no par value; authorized
      15,000,000 shares; issued 8,946,468 shares                33,549          33,549
     Additional paid-in capital                                  4,350           4,183
     Retained earnings                                         130,124         126,082
     Accumulated other comprehensive income                       (290)           (290)
                                                              --------        --------
                                                               167,733         163,524
     Treasury stock at cost
      (1999-1,682,766 shares; 1998-1,700,552 shares)           (12,265)        (12,299)
     Unearned compensation  restricted stock                    (1,515)         (1,971)
                                                              --------        --------
          Total Stockholders' Equity                           153,953         149,254
                                                              --------        --------
                                                              $299,558        $289,383
                                                              ========        ========
</TABLE>
See Notes to Consolidated Financial Statements.

                                      -5-
<PAGE>
 
Item 1.  Financial Statements (Continued)

                             PITT-DES MOINES, INC.
                     Consolidated Statements of Cash Flows
                                  (Unaudited)

                                                      For the three months ended
                                                                March 31,
(in thousands)                                              1999        1998
                                                          ---------   ---------
Cash Flow From Operating Activities
     Net income                                           $  5,297    $  4,168
     Adjustments to reconcile net income to net
      cash utilized by operating activities:
         Depreciation                                        1,871       1,547
         Gain on sale of assets                               (950)        (18)
         Minority interest, net of dividends paid               10           8
         Other non-cash credits, net                           (30)       (120)
         Change in operating assets and liabilities
          (using) providing cash:
         Accounts receivable                                (6,863)     (6,696)
         Inventories                                         5,968       1,125
         Prepaid expenses                                   (2,414)       (436)
         Costs, estimated profits and billings, net          8,916       5,320
         Accounts payable                                  (17,028)    (13,941)
         Accrued liabilities                                  (367)        903
         Income taxes                                        1,562         833
                                                          --------    --------
     Net cash utilized by operating activities              (4,028)     (7,307)
 
Cash Flows from Investing Activities
     Capital expenditures                                   (3,476)     (2,751)
     Proceeds from sale of assets                            2,979          33
     Acquisitions, net of cash acquired                     (2,182)          0
     Change in investments and other assets                   (162)       (325)
                                                          --------    --------
     Net cash utilized by investing activities              (2,841)     (3,043)
 
Cash Flows from Financing Activities
     Proceeds from revolving credit facility                17,000      10,000
     Dividends paid                                         (1,232)     (1,057)
     Other                                                      94         427
                                                          --------    --------
     Net cash provided by financing activities              15,862       9,370
                                                          --------    --------
     (Decrease) increase in cash and cash equivalents        8,993        (980)
     Cash and cash equivalents at beginning of year          8,447      12,037
                                                          --------    --------
Cash and cash equivalents at end of period                $ 17,440    $ 11,057
                                                          ========    ========

See Notes to Consolidated Financial Statements.

                                      -6-
<PAGE>
 
Item 1.  Financial Statements (Continued)

                             PITT-DES MOINES, INC.
                  Notes to Consolidated Financial Statements
                                  (Unaudited)

Note A.  Significant Accounting Policies

Basis of Presentation

The accompanying unaudited consolidated financial statements have been prepared
in accordance with generally accepted accounting principles for interim
financial information and with the instructions to Form 10-Q and Article 10 of
Regulation S-X.  Accordingly, they do not include all of the information and
footnotes required by generally accepted accounting principles for complete
financial statements.  In the opinion of management, all adjustments (consisting
of normal recurring accruals) considered necessary for a fair presentation have
been included.  Operating results for the three months ended March 31, 1999 are
not necessarily indicative of the results that may be expected for the year
ending December 31, 1999.  The December 31, 1998 Consolidated Statement of
Financial Condition was derived from audited financial statements.  For further
information, refer to the consolidated financial statements and footnotes
thereto included in the Company's Annual Report on Form 10-K for the year ended
December 31, 1998.

Reclassifications

Certain prior-year amounts have been reclassified to conform to the current-year
presentation.

Note B.  Earnings Per Share

The following table sets forth the computation of earnings per share and
earnings per share assuming dilution:
 
                                                    Three months
                                                   ended March 31,
                                                   ----------------     
(in thousands, except per share amounts)            1999      1998
                                                   ------    ------
Numerator:
Net income                                         $5,297    $4,168
                                                   ======    ======
 
Denominator:
Weighted-average shares                             7,106     7,032
Employee stock options and restricted stock           345       166
                                                   ------    ------
Weighted-average shares-assuming dilution           7,451     7,198
                                                   ======    ======
 
Earnings per share                                 $ 0.75    $ 0.59
                                                   ======    ======
 
Earnings per share-assuming dilution               $ 0.71    $ 0.58
                                                   ======    ======

                                      -7-
<PAGE>
 
Item 1.  Financial Statements (Continued)

Note C.  Costs and Estimated Profits on Uncompleted Contracts

Costs and estimated profits on uncompleted contracts are summarized as follows:

 
                                              March 31,     December 31,
(in thousands)                                  1999           1998
                                             ---------       ---------
Costs incurred on uncompleted contracts      $ 732,018       $ 608,870
Estimated profits                               90,213          71,450
                                             ---------       ---------
                                               822,231         680,320
Less:  Billings to date                       (782,221)       (631,394)
                                             ---------       ---------
                                             $  40,010       $  48,926
                                             =========       =========


Costs, estimated profits and billings on uncompleted contracts are included in
the accompanying Consolidated Statements of Financial Condition under the
following captions:
 
                                                    March 31,     December 31,
(in thousands)                                        1999            1998
                                                    --------        --------
Costs and estimated profits in excess of billings   $ 60,660        $ 63,700
Billings in excess of costs and estimated profits    (20,650)        (14,774)
                                                    --------        --------
                                                    $ 40,010        $ 48,926
                                                    ========        ========

Included in costs and estimated profits in excess of billings on uncompleted
contracts was approximately $6.5 million at March 31, 1999 and December 31,
1998, relating to an unapproved change order arising from a dispute over design
and specification changes on a project that has been completed.  On May 14,
1996, the Company filed an action in the United States District Court for the
Northern District of Illinois (Eastern Division) captioned PITT-DES MOINES, INC.
V. METROPOLITAN PIER & EXPOSITION AUTHORITY ET AL. seeking reimbursement in
excess of $15.0 million for additional work and making other claims in
connection with an unapproved change order.  On June 4, 1996, certain of the
defendants in said action made counterclaims against the Company in amounts
approximating $3.5 million.  While counsel believes that the Company has a legal
basis for the claim, neither management nor counsel is able to predict with
certainty the ultimate resolution of this matter.  As additional information
becomes available, the Company may revise its estimate of potential recovery,
which could result in a material adjustment to the results of operations in
future periods.

                                      -8-
<PAGE>
 
Item 1.  Financial Statements (Continued)

Note D.  Contingencies

As previously reported, in a decision dated February 18, 1999, the United States
Court of Appeals for the Seventh Circuit affirmed the Company's July 31, 1997
conviction for two misdemeanor violations of federal Occupational Safety and
Health Administration regulations.  As a result of that conviction, other
claims, actions, or proceedings may be instituted against the Company.  The
Company cannot predict the likelihood of such a claim, action or proceeding
being instituted against it, and cannot assess the availability of any insurance
coverage or the possibility or materiality of an adverse result in the event of
any such claim, action or proceeding in advance of a claim, action or proceeding
being instituted.

On June 20, 1996 the Company was served with a subpoena to appear and produce
documents before a grand jury of the United States District Court for the
Western District of Wisconsin in connection with the United States Department of
Justice Antitrust Division's investigation of bid rigging and other criminal
violations in the steel bridge fabrication industry.  The Company has been
informed that it is not the target of the investigation at present but that it
and other companies in the steel bridge fabrication industry are the subjects of
the investigation.

While the investigation remains pending, the Company does not believe it will
become a target of the investigation or that a criminal action will be
instituted against it in these matters.  If the Company becomes a target or if a
criminal investigation were instituted, the Company believes that it would have
significant and meritorious defenses to any such charges and would vigorously
defend against them.

Various claims and legal proceedings are brought against the Company arising
from the normal course of business.  Although counsel is unable to predict with
certainty the ultimate outcome, management and counsel believe the Company has
significant and meritorious defenses to any claims, and intend to pursue them
vigorously.

The Company's operations, including idle facilities and other properties, are
subject to and affected by federal, state and local laws and regulations
regarding the protection of the environment.  The Company accrues for
environmental costs where such obligations are either known or considered
probable and can be reasonably estimated.

The Company is participating as a potentially responsible party (PRP) at three
different sites, and has been requested to participate as a PRP at one
additional site, pursuant to proceedings under the Comprehensive Environmental
Response, Compensation and Liability Act (CERCLA).  Other parties have also been
identified as PRP's at the sites.  Investigative and/or remedial activities are
ongoing.  The Company believes, based upon information presently available to
it, that the cost of such future activities will not have a material effect on
the Company's financial position, results of operations or liquidity.
Additionally, amounts reflected in results of operations and in the statements
of financial condition during the three years ended December 31, 1998, for
investigative and/or remedial activities have also not been material.  However,
the imposition of more stringent requirements under environmental laws or
regulations, new developments or changes regarding site cleanup costs or the
allocation of such costs among PRP's or a

                                      -9-
<PAGE>
 
Item 1.  Financial Statements (Continued)

Note D.  Contingencies (Continued)

determination that the Company is potentially responsible for the release of
hazardous substances at sites other than those currently identified, could
result in additional costs.

Management believes that the ultimate outcome of any matter currently pending
against the Company will not materially affect the financial position of the
Company although such outcome could be material to the reported results of
operations for the period in which it occurs.


Note E.  Business Segment Information

The Company has two reportable operating segments; Engineering and Construction
and Steel Distribution.  The accounting policies of the reportable segments are
the same as those described in the summary of significant accounting policies in
the Company's 1998 Annual Report except that inventory is accounted for on a
First-In, First-Out basis at the segment level compared to a Last-In, First-Out
(LIFO) basis at the consolidated level, and the Company does not allocate
certain items to its segments including general corporate expenses, incentive
stock plan charges, other income (expense), income tax expense and adjustments
to the LIFO inventory reserve.
 
                                          Three months
                                         ended March 31,
                                     ------------------------
                                       1999            1998
                                     --------        --------
Earned Revenue:
  Engineering and Construction       $ 99,512        $ 76,888
  Steel Distribution                   44,566          47,372
  Corporate and Other                  (1,232)           (890)
                                     --------        --------
                                     $142,846        $123,370
                                     ========        ========
 
Income (Loss) from Operations:
  Engineering and Construction       $  7,881        $  6,148
  Steel Distribution                    3,140           3,541
  Corporate and Other                  (2,539)         (2,166)
                                     --------        --------
                                     $  8,482        $  7,523
                                     ========        ========

                                      -10-
<PAGE>
 
Item 2.  Management's Discussion and Analysis of Financial Condition and Results
         of Operations

RESULTS OF OPERATIONS

THREE MONTHS ENDED MARCH 31, 1999 COMPARED WITH THREE MONTHS ENDED MARCH 31,
1998.

The Company reported net income of $5.3 million, or $0.71 per diluted share, on
earned revenue of $142.8 million for the quarter ended March 31, 1999.  These
results compare with net income of $4.2 million, or $.58 per diluted share, on
earned revenue of $123.4 million for the first quarter of 1998.

ENGINEERING AND CONSTRUCTION

Engineering and Construction posted earned revenue of $99.5 million,
representing an increase of $22.6 million, or 29 percent, over the prior year
quarter.  All product groups experienced double-digit percentage growth over the
first quarter of 1998, with the Liquid and Cryogenic Storage and Steel Bridge
products groups accounting for the majority of the increase.  The Liquid and
Cryogenic Storage group benefited from strong demand for conventional storage
tanks, while the Steel Bridge growth is attributable to increased federal and
state infrastructure spending.

Selling, general and administrative (S,G&A) expense as a percentage of earned
revenue improved 1.8 percentage points to 6.0 percent, compared with 7.8 percent
in the first quarter of 1998.  Income from operations rose $1.7 million to $7.9
million for the first quarter due to the earned revenue growth and leverage of
the SG&A expense line over the prior year.

New awards were $124.3 million for the first quarter.  Backlog rose 24 percent
over the previous year levels, to $327.8 million at March 31, 1999.  As
indicated in "Costs and Estimated Profits on Uncompleted Contracts" in Notes to
Consolidated Financial Statements, included in costs and estimated profits in
excess of billings on uncompleted contracts at March 31, 1999 was approximately
$6.5 million relating to an unapproved change order arising from a dispute over
design and specification changes.

STEEL DISTRIBUTION

Steel Distribution's earned revenue decreased $2.8 million quarter-to-quarter
from $47.4 million to $44.6 million in 1999.  Lower transaction prices in the
marketplace accounted for the majority of the decrease from the prior year.

SG&A expense in absolute dollars approximated first quarter 1998 levels;
however, as a percentage of earned revenue SG&A expense increased to 8.1
percent, from 7.4 percent a year ago, due to the lower 1999 sales.  Income from
operations of $3.1 million was down from $3.5 million in 1998 as a result of the
aforementioned decrease in earned revenue.

                                      -11-
<PAGE>
 
Item 2.  Management's Discussion and Analysis of Financial Condition and Results
         of Operations (Continued)

OTHER

Corporate unallocated expenses, consisting of salaries, benefits, outside
professional services, taxes and insurance, were $2.5 million in the first
quarter of 1999 compared with $2.2 million for the prior year quarter.  The
increase in 1999 relates primarily to compensation expense recognized under an
incentive stock plan for which no amounts were included in the first quarter of
1998.

Interest expense of $0.7 million in 1999 compares with $0.3 million in the prior
year.  Interest expense is directly related to the level of net borrowings the
Company maintains throughout the period.  The increase in interest expense for
1999 resulted from the higher level of borrowings to fund capital expansion and
to finance general working capital needs.  On March 31, 1999 the Company had $52
million of outstanding debt under its revolving credit facility compared with
$21 million at March 31, 1998.

The gain on sale of assets was $1.0 million in 1999, attributable to the sale of
idle property.

As indicated in the "Contingencies" section of the Notes to Consolidated
Financial Statements, the Company's future results of operations could be
materially adversely affected by the Company's conviction on July 31, 1997 of
two misdemeanors for violations of the Occupational Safety Health Act (and
regulations promulgated thereunder)(see Note D "Contingencies" Notes to
Consolidated Financial Statements).

YEAR 2000

The Company initiated a review of its software systems in 1997 in view of the
fact that certain systems may not properly recognize dates after the year 1999,
which could cause those systems to produce invalid results or fail to operate.
This is commonly referred to as "the Year 2000 problem."  The Company's Year
2000 plan encompasses three main phases:  Assessment, Remediation and Testing.
All phases of the Year 2000 plan have generally been conducted by Information
Technology personnel.  While the Company has not tracked these costs separately,
it does not believe the impact of the Year 2000 remediation efforts has had a
material impact on the Company's results of operations for the periods
presented, or that any additional costs will have a material impact on the
Company's future results of operations.

The Company has completed the assessment phase of all major information
technology systems.  The majority of these systems, including software
applications, have been updated through the normal course of upgrades and
program maintenance.  The remaining systems have been assessed and the Company
has established plans for remediation and testing which the Company anticipates
will conclude by the second quarter of 1999.

                                      -12-
<PAGE>
 
Item 2.  Management's Discussion and Analysis of Financial Condition and Results
         of Operations (Continued)

YEAR 2000 (Continued)

The Company has substantially completed the assessment phase of operating
equipment which utilizes non-information technology systems, typically embedded
technology such as micro controllers.  In most cases the Company has either made
the recommended changes, or contacted vendors to determine whether the equipment
will experience Year 2000 problems.  The majority of the remaining systems have
been assessed and the Company has established plans for remediation and testing
which the Company anticipates will conclude by the third quarter of 1999.

The Company has contacted its significant suppliers and financial institutions
but has not yet received adequate responses from all of them to determine the
status of their Year 2000 compliance.  Management continues to evaluate what
impact the failure of these organizations to become Year 2000 compliant could
have on the Company's consolidated financial position or results of operations.

Management of the Company believes its Year 2000 program is addressing the Year
2000 issue in a timely manner.  However, as noted above, the Company has not yet
completed all necessary phases of its Year 2000 program.  In the event that the
Company does not complete any remaining phases, the Company may have to conduct
certain operations in an alternative manner.  There can be no assurance that the
Company's results of operations would not be materially and adversely affected
by the delays and inefficiencies inherent in conducting operations in such a
manner.  In addition, disruptions in the general economy or from third parties
resulting from Year 2000 issues could also materially adversely affect the
Company.  The amount of potential liability and lost earned revenue, as a result
of the Company's failure to be Year 2000 compliant, a third party's failure to
be Year 2000 compliant or an economic slowdown, cannot be reasonably estimated.

The Company is currently evaluating contingency plans in the event of a Year
2000 failure.  The Company anticipates that these contingency plans will be
completed by the end of the second quarter of 1999.

LIQUIDITY AND CAPITAL RESOURCES

During the three months ended March 31, 1999, the Company's primary sources of
liquidity were proceeds from its revolving credit facility and cash flow
generated from operations which were used for investing activities and to fund
the growth in working capital.  Working capital increased $19.2 million from
$118.5 million at December 31, 1998 to $137.7 million at March 31, 1999.

Net cash utilized by operating activities of $4.0 million decreased by $3.3
million when compared with the same period in 1998.  An increase in net income
coupled with a decrease in inventories accounted for a majority of the
improvement over the first quarter of 1998.  The changes in operating assets and
liabilities vary from period to period and are affected by the mix, stage of
completion and commercial terms of contracts.

                                      -13-
<PAGE>
 
Item 2.  Management's Discussion and Analysis of Financial Condition and Results
         of Operations (Continued)

LIQUIDITY AND CAPITAL RESOURCES (Continued)

Net cash utilized by investing activities of $2.8 million for the three months
ended March 31, 1999, consisted of capital expenditures and the acquisition of
the remaining 18 percent interest in Oregon Culvert Company, Inc.  The Company
expended $3.5 million for capital improvements, related primarily to
construction of a new steel service center in Woodland, Washington, and realized
$3.0 million in proceeds from the sale of idle property.  The Company
anticipates that capital expenditures for fiscal year 1999 will approximate the
level of depreciation and amortization, although there can be no assurance that
such levels will not increase or decrease.

The Company continues to evaluate and selectively pursue opportunities for
growth or expansion of its business through investment in or acquisition of
complementary businesses.  Acquisition and investment candidates are evaluated
based on various criteria in a process which includes due diligence, management
reviews and board approval.  Management anticipates that investment and / or
acquisition opportunities will be available to the Company and intends to
investigate those opportunities for future growth and expansion of its business.
The Company expects that any such acquisitions will be financed from cash on
hand or available under the Company's revolving credit facility.  In certain
cases, acquisitions may be funded using stock or pursuant to stand-alone credit
facilities.

Cash provided by financing activities consisted primarily of proceeds from the
Company's revolving credit facility.  The Company paid cash dividends of $1.2
million, or $0.17 per share, compared with $1.1 million, or $0.15 per share,
during the three months ended March 31, 1999 and 1998, respectively.

The Company has on hand and access to sufficient sources of funds to meet its
anticipated operating, expansion and capital needs.  These sources include cash
on hand and the unused portion of a $70.0 million unsecured revolving credit
facility which expires on January 31, 2002.  On May 10, 1999, $52 million of
borrowings and $10.8 million of stand-by letters of credit were outstanding
under this credit facility.  The Company expects to borrow under this credit
facility for working capital requirements during 1999.

FORWARD-LOOKING STATEMENTS

Any of the comments in this quarterly report that refer to the Company's
estimated or future results, margins on existing or future projects, long-term
profitability, Year 2000 issues and demand and growth trends for Pitt-Des
Moines, Inc., are forward-looking and reflect the Company's current analysis of
existing trends and information.  Actual results may differ materially from
current expectations or projections based on a number of factors affecting the
Company's businesses.  The Company's estimates of future performance depend on,
among other things, the likelihood of receiving certain new awards.  While these
estimates are based on the good faith judgment of management, these estimates
frequently change based on new facts which

                                      -14-
<PAGE>
 
Item 2.  Management's Discussion and Analysis of Financial Condition and Results
         of Operations (Continued)

FORWARD-LOOKING STATEMENTS (Continued)

become available.  In addition, the timing of receipt of revenue by the Company
from engineering and construction projects can be affected by a number of
factors outside the control of the Company.  The Company's businesses are also
subject to fluctuations in demand and to changing global economic and political
conditions which are beyond the control of the Company and may cause actual
results to differ from the forward-looking statements contained in this
quarterly report.

These forward-looking statements represent the Company's judgment only as of the
date of this quarterly report.  As a result, the reader is cautioned not to rely
on these forward-looking statements.  The Company disclaims any intent or
obligation to update these forward-looking statements.



Item 3.  Quantitative and Qualitative Disclosures About Market Risk

Due to current conditions in the credit markets and considering the favorable
terms of the Company's credit facility, management believes interest rate
exposure is minimal.

The Company has limited operations outside the United States.  As such, there is
limited exposure to the Company's future earnings due to changes in foreign
currency exchange rates.  A 10 percent appreciation of the United States dollar
against the related currencies would not have a significant effect on the future
earnings of the Company.

                                      -15-
<PAGE>
 
                          Part II - Other Information

Item 1.  Legal Proceedings

         Refer to Part I Item 1, Notes C and D of the Notes to Consolidated
         Financial Statements for information, which information is incorporated
         herein by reference.


Item 6.  Exhibits and Reports on Form 8-K

    (a)  Exhibits

         (3.1)  Articles of Incorporation, as amended to date (filed herewith)

         (27)  Financial Data Schedule.

    (b)  Reports on Form 8-K.
 
         There were no reports on Form 8-K filed by the Company during the
         quarter ended March 31, 1999.

                                      -16-
<PAGE>
 
                                  Signatures



Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.



                                           Pitt-Des Moines, Inc.
                                     --------------------------------
                                                (Registrant)



                                     Principal Executive Officer:



Date:  May 14, 1999                  By: /s/ Wm. W. McKee
                                         --------------------------------
                                         Wm. W. McKee
                                         (President and
                                         Chief Executive Officer)



                                     Principal Financial Officer:



Date:  May 14, 1999                  By: /s/ R. A. Byers
                                         -------------------------------
                                         R. A. Byers
                                         (Vice President
                                         Finance and Treasurer)

                                      -17-
<PAGE>
 
                                 EXHIBIT INDEX


Exhibit
Number
------

  (3.1)  Articles of Incorporation, as amended to date


  (27)   Financial Data Schedule

                                      -18-