<PAGE>   1
                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                                    FORM 10-Q


[X]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES 
     EXCHANGE ACT OF 1934 FOR THE QUARTERLY PERIOD ENDED MARCH 31, 1998

                                       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 0-21518

                            IEA INCOME FUND XII, L.P.
             (Exact name of registrant as specified in its charter)


           California                                          94-3143940
 (State or other jurisdiction of                            (I.R.S. Employer
 incorporation or organization)                            Identification No.)

         444 Market Street, 15th Floor, San Francisco, California 94111
               (Address of principal executive offices)   (Zip Code)

                                 (415) 677-8990
              (Registrant's telephone number, including area code)


Indicate by check mark 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 [ ].


<PAGE>   2
                            IEA INCOME FUND XII, L.P.

                  REPORT ON FORM 10-Q FOR THE QUARTERLY PERIOD
                              ENDED MARCH 31, 1998

                                TABLE OF CONTENTS



<TABLE>
<CAPTION>
                                                                               PAGE
<S>                                                                            <C>
PART I - FINANCIAL INFORMATION

 Item 1. Financial Statements

         Balance Sheets - March 31, 1998 (unaudited) and December 31, 1997      4

         Statements of Operations for the three months ended March 31, 
            1998 and 1997 (unaudited)                                           5

         Statements of Cash Flows for the three months ended 
            March 31, 1998 and 1997 (unaudited)                                 6

         Notes to Financial Statements (unaudited)                              7

 Item 2. Management's Discussion and Analysis of Financial Condition and 
            Results of Operations                                               10


PART II - OTHER INFORMATION

 Item 6. Exhibits and Reports on Form 8-K                                       14
</TABLE>



                                       2
<PAGE>   3
                         PART I - FINANCIAL INFORMATION


 Item 1. Financial Statements

         Presented herein are the Registrant's balance sheets as of March 31,
         1998 and December 31, 1997, statements of operations for the three
         months ended March 31, 1998 and 1997, and statements of cash flows for
         the three months ended March 31, 1998 and 1997.



                                       3
<PAGE>   4
                            IEA INCOME FUND XII, L.P.

                                 BALANCE SHEETS

                                   (UNAUDITED)


<TABLE>
<CAPTION>
                                                                  March 31,        December 31,
                                                                    1998               1997
                                                                ------------       ------------
<S>                                                             <C>                <C>         
                 Assets
Current assets:
   Cash and cash equivalents, includes $2,069,622 at March
      31, 1998 and $1,883,189 at December 31, 1997 in
      interest-bearing accounts                                 $  2,088,346       $  1,883,389
   Net lease receivables due from Leasing Company
      (notes 1 and 2)                                              1,041,410          1,094,453
                                                                ------------       ------------

         Total current assets                                      3,129,756          2,977,842
                                                                ------------       ------------

Container rental equipment, at cost                               63,012,440         63,162,608
   Less accumulated depreciation                                  20,394,561         19,524,264
                                                                ------------       ------------
      Net container rental equipment                              42,617,879         43,638,344
                                                                ------------       ------------

                                                                $ 45,747,635       $ 46,616,186
                                                                ============       ============

            Liabilities and Partners' Capital

Current liabilities:
   Accrued expenses                                             $    462,948       $    462,948
                                                                ------------       ------------

         Total current liabilities                                   462,948            462,948
                                                                ------------       ------------

Partners' capital (deficit):
   General partner                                                   (29,970)           (25,736)
   Limited partners                                               45,314,657         46,178,974
                                                                ------------       ------------

         Total partners' capital                                  45,284,687         46,153,238
                                                                ------------       ------------

                                                                $ 45,747,635       $ 46,616,186
                                                                ============       ============
</TABLE>

   The accompanying notes are an integral part of these financial statements.



                                       4
<PAGE>   5
                            IEA INCOME FUND XII, L.P.

                            STATEMENTS OF OPERATIONS

                                   (UNAUDITED)


<TABLE>
<CAPTION>
                                                          Three Months Ended
                                                      --------------------------
                                                       March 31,       March 31,
                                                         1998            1997
                                                      ----------      ----------
<S>                                                   <C>             <C>       
Net lease revenue (notes 1 and 3)                     $1,389,954      $1,396,464

Other operating expenses:
  Depreciation                                           921,226         986,575
  Other general and administrative expenses               28,528          17,259
                                                      ----------      ----------
                                                         949,754       1,003,834
                                                      ----------      ----------
    Earnings from operations                             440,200         392,630

Other income:
  Interest income                                         27,466          27,105
  Net gain on disposal of equipment                        4,496           9,328
                                                      ----------      ----------
                                                          31,962          36,433
                                                      ----------      ----------

    Net earnings                                      $  472,162      $  429,063
                                                      ==========      ==========

Allocation of net earnings:
  General partner                                     $   62,802      $   77,633
  Limited partners                                       409,360         351,430
                                                      ----------      ----------

                                                      $  472,162      $  429,063
                                                      ==========      ==========

Limited partners' per unit share of net earnings      $     0.12      $     0.10
                                                      ==========      ==========
</TABLE>



   The accompanying notes are an integral part of these financial statements.



                                       5
<PAGE>   6
                            IEA INCOME FUND XII, L.P.

                            STATEMENTS OF CASH FLOWS

                                   (UNAUDITED)


<TABLE>
<CAPTION>
                                                                  Three Months Ended
                                                            -----------------------------
                                                              March 31,         March 31,
                                                                1998              1997
                                                            -----------       -----------
<S>                                                         <C>               <C>        
Net cash provided by operating activities                   $ 1,330,865       $ 1,508,214

Cash flows provided by (used in) investing activities:
  Proceeds from disposal of equipment                           214,805            50,651
  Purchase of container rental equipment                             --          (374,111)
  Acquisition fees paid to general partner                           --           (93,706)
                                                            -----------       -----------

Net cash provided by (used in) investing activities             214,805          (417,166)
                                                            -----------       -----------

Cash flows used in financing activities:
  Distribution to partners                                   (1,340,713)       (1,602,692)
                                                            -----------       -----------


Net increase (decrease) in cash and cash equivalents            204,957          (511,644)


Cash and cash equivalents at January 1                        1,883,389         2,262,639
                                                            -----------       -----------


Cash and cash equivalents at March 31                       $ 2,088,346       $ 1,750,995
                                                            ===========       ===========
</TABLE>




   The accompanying notes are an integral part of these financial statements.



                                       6
<PAGE>   7
                            IEA INCOME FUND XII, L.P.

                     NOTES TO UNAUDITED FINANCIAL STATEMENTS


(1)  Summary of Significant Accounting Policies

     (a) Nature of Operations

         IEA Income Fund XII, L.P. (the "Partnership") is a limited partnership
         organized under the laws of the State of California on August 28, 1991
         for the purpose of owning and leasing marine cargo containers. Cronos
         Capital Corp. ("CCC") is the general partner and, with its affiliate
         Cronos Containers Limited (the "Leasing Company"), manages and controls
         the business of the Partnership. The Partnership shall continue until
         December 31, 2011, unless sooner terminated upon the occurrence of
         certain events.

         The Partnership commenced operations on January 31, 1992, when the
         minimum subscription proceeds of $2,000,000 were obtained. As of March
         31, 1998, the Partnership operated 9,293 twenty-foot, 5,272 forty-foot
         and 208 forty-foot high-cube marine dry cargo containers, as well as
         199 twenty-foot and 305 forty-foot marine refrigerated cargo
         containers.

         The Partnership offered 3,750,000 units of limited partnership interest
         at $20 per unit, or $75,000,000. The offering terminated on November
         30, 1992, at which time 3,513,594 limited partnership units had been
         purchased.

     (b) Leasing Company and Leasing Agent Agreement

         The Partnership has entered into a Leasing Agent Agreement whereby the
         Leasing Company has the responsibility to manage the leasing operations
         of all equipment owned by the Partnership. Pursuant to the Agreement,
         the Leasing Company is responsible for leasing, managing and re-leasing
         the Partnership's containers to ocean carriers and has full discretion
         over which ocean carriers and suppliers of goods and services it may
         deal with. The Leasing Agent Agreement permits the Leasing Company to
         use the containers owned by the Partnership, together with other
         containers owned or managed by the Leasing Company and its affiliates,
         as part of a single fleet operated without regard to ownership. Since
         the Leasing Agent Agreement meets the definition of an operating lease
         in Statement of Financial Accounting Standards (SFAS) No. 13, it is
         accounted for as a lease under which the Partnership is lessor and the
         Leasing Company is lessee.

         The Leasing Agent Agreement generally provides that the Leasing Company
         will make payments to the Partnership based upon rentals collected from
         ocean carriers after deducting direct operating expenses and management
         fees to CCC and the Leasing Company. The Leasing Company leases
         containers to ocean carriers, generally under operating leases which
         are either master leases or term leases (mostly two to five years).
         Master leases do not specify the exact number of containers to be
         leased or the term that each container will remain on hire but allow
         the ocean carrier to pick up and drop off containers at various
         locations; rentals are based upon the number of containers used and the
         applicable per-diem rate. Accordingly, rentals under master leases are
         all variable and contingent upon the number of containers used. Most
         containers are leased to ocean carriers under master leases; leasing
         agreements with fixed payment terms are not material to the financial
         statements. Since there are no material minimum lease rentals, no
         disclosure of minimum lease rentals is provided in these financial
         statements.

     (c) Basis of Accounting

         The Partnership utilizes the accrual method of accounting. Net lease
         revenue is recorded by the Partnership in each period based upon its
         leasing agent agreement with the Leasing Company. Net lease revenue is
         generally dependent upon operating lease rentals from operating lease
         agreements between the Leasing Company and its various lessees, less
         direct operating expenses and management fees due in respect of the
         containers specified in each operating lease agreement.



                                       7
<PAGE>   8
                            IEA INCOME FUND XII, L.P.

                     NOTES TO UNAUDITED FINANCIAL STATEMENTS


     (d) Financial Statement Presentation

         These financial statements have been prepared without audit. Certain
         information and footnote disclosures normally included in financial
         statements prepared in accordance with generally accepted accounting
         procedures have been omitted. It is suggested that these financial
         statements be read in conjunction with the financial statements and
         accompanying notes in the Partnership's latest annual report on Form
         10-K.

         The preparation of financial statements in conformity with generally
         accepted accounting principles (GAAP) requires the Partnership to make
         estimates and assumptions that affect the reported amounts of assets
         and liabilities and disclosure of contingent assets and liabilities at
         the date of the financial statements and the reported amounts of
         revenues and expenses during the reported period. Actual results could
         differ from those estimates.

         The interim financial statements presented herewith reflect all
         adjustments of a normal recurring nature which are, in the opinion of
         management, necessary to a fair statement of the financial condition
         and results of operations for the interim periods presented.


(2)  Net Lease Receivables Due from Leasing Company

     Net lease receivables due from the Leasing Company are determined by
     deducting direct operating payables and accrued expenses, base management
     fees payable, and reimbursed administrative expenses payable to CCC and its
     affiliates from the rental billings payable by the Leasing Company to the
     Partnership under operating leases to ocean carriers for the containers
     owned by the Partnership. Net lease receivables at March 31, 1998 and
     December 31, 1997 were as follows:


<TABLE>
<CAPTION>
                                                                              March 31,       December 31,
                                                                                1998             1997
                                                                              ----------      ----------
<S>                                                                           <C>             <C>
         Lease receivables, net of doubtful accounts of $169,146
            at March 31, 1998 and $126,327 at December 31, 1997               $1,998,057      $2,117,313
         Less:
         Direct operating payables and accrued expenses                          479,899         512,846
         Damage protection reserve                                               174,393         179,744
         Base management fees                                                    264,549         289,537
         Reimbursed administrative expenses                                       37,806          40,733
                                                                              ----------      ----------

                                                                              $1,041,410      $1,094,453
                                                                              ==========      ==========
</TABLE>



                                       8
<PAGE>   9
                            IEA INCOME FUND XII, L.P.

                     NOTES TO UNAUDITED FINANCIAL STATEMENTS


(3)  Net Lease Revenue

     Net lease revenue is determined by deducting direct operating expenses,
     base management fees and reimbursed administrative expenses to CCC and its
     affiliates from the rental revenue billed by the Leasing Company under
     operating leases to ocean carriers for the containers owned by the
     Partnership. Net lease revenue for the three-month periods ended March 31,
     1998 and 1997 was as follows:


<TABLE>
<CAPTION>
                                                      Three Months Ended
                                                  --------------------------
                                                   March 31,       March 31,
                                                     1998            1997
                                                  ----------      ----------
<S>                                               <C>             <C>       
         Rental revenue                           $2,179,358      $2,336,805
         Less:
         Rental equipment operating expenses         487,720         659,668
         Base management fees                        149,902         161,762
         Reimbursed administrative expenses          151,782         118,911
                                                  ----------      ----------

                                                  $1,389,954      $1,396,464
                                                  ==========      ==========
</TABLE>




                                       9
<PAGE>   10
Item 2. Management's Discussion and Analysis of Financial Condition and Results
        of Operations

It is suggested that the following discussion be read in conjunction with the
Registrant's most recent annual report on Form 10-K.

1)   Material changes in financial condition between March 31, 1998 and December
     31, 1997.

     At March 31, 1998, the Registrant had $2,088,346 in cash and cash
     equivalents, an increase of $204,957 from the December 31, 1997 cash
     balances. At March 31, 1998, the Registrant had approximately $352,000 in
     cash generated from equipment sales reserved as part of its cash balances.
     Throughout the remainder of 1998, the Registrant expects to continue using
     cash generated from equipment sales to purchase and replace containers
     which have been lost or damaged beyond repair.

     The Registrant's operating performance contributed to a 5% decline in net
     lease receivables at March 31, 1998 when compared to December 31, 1997. The
     Registrant's cash distribution from operations for the first quarter of
     1998 was 7.25% (annualized) of the limited partners' original capital
     contributions, unchanged from the fourth quarter of 1997. These
     distributions are directly related to the Registrant's results from
     operations and may fluctuate accordingly.

     Market conditions that existed during 1997 persisted through the first
     quarter of 1998. Low container prices, favorable interest rates and the
     abundance of available capital continued to discourage ocean carriers and
     other transport companies from leasing containers at levels comparable to
     previous years. By the end of 1997, the volatility of the Hong Kong and
     other Asian financial markets began to negatively impact trade, shipping
     and container leasing. As a result, the Registrant's dry cargo and
     refrigerated container utilization rates declined from 81% and 86%,
     respectively, at December 31, 1997 to 79% and 84%, respectively, at March
     31, 1998. Per-diem rental rates continued to remain under pressure as a
     result of the following factors: start-up leasing companies offering new
     containers and low rental rates in an effort to break into the leasing
     market; established leasing companies reducing rates to very low levels;
     and a continuing oversupply of containers. These leasing market conditions
     impacted the Registrant's financial condition and operating performance
     during the first quarter of 1998.

2)   Material changes in the results of operations between the three-month
     period ended March 31, 1998 and the three-month period ended March 31,
     1997.

     Net lease revenue for the three-month period ended March 31, 1998 was
     $1,389,954, a decline of less than 1% from the same period in the prior
     year. Gross rental revenue (a component of net lease revenue) for the
     three-month period ended March 31, 1998 was $2,179,358, reflecting a
     decline of 7% from the same period in the prior year. Gross lease revenue
     was primarily impacted by lower per-diem rental rates and utilization
     levels. Average dry cargo container per-diem rental rates for the
     three-month period ended March 31, 1998 declined approximately 10%, when
     compared to the same period in the prior year. Average refrigerated
     container per-diem rental rates for the three-month period ended March 31,
     1998 declined approximately 13%, when compared to the same period in the
     prior year. Dry cargo container utilization, has increased since December
     31, 1997, and recovered to the same levels experienced during the
     three-month period ended March 31, 1997.



                                       10
<PAGE>   11
     The Registrant's average fleet size and utilization rates for the
     three-month periods ended March 31, 1998 and 1997 were as follows:


<TABLE>
<CAPTION>
                                                         Three Months Ended
                                                        -----------------------
                                                        March 31,     March 31,
                                                         1998           1997
                                                        ---------     ---------
<S>                                                     <C>           <C>
         Average fleet size (measured in twenty-foot
            equivalent units (TEU))
               Dry cargo containers                       20,277       20,299
               Refrigerated containers                       809          811
         Average Utilization
               Dry cargo containers                           78%          76%
               Refrigerated containers                        85%          85%
</TABLE>


     Rental equipment operating expenses were 22% of the Registrant's gross
     lease revenue during the three-month period ended March 31, 1998, as
     compared to 28% during the three-month period ended March 31, 1997. This
     decline was largely attributable to a decrease in costs associated with
     slightly higher utilization levels, including handling and storage.

     The Registrant disposed of 25 twenty-foot, 17 forty foot and one forty-foot
     high-cube marine dry cargo containers during the first quarter of 1998, as
     compared to four twenty-foot and five forty-foot marine dry cargo
     containers during the same period in the prior year. The decision to repair
     or dispose of a container is made when it is returned by a lessee. This
     decision is influenced by various factors including the age, condition,
     suitability for continued leasing, as well as the geographical location of
     the container when disposed. These factors also influence the amount of
     sales proceeds received and the related gain on container disposals.

     As reported in the Registrant's Current Report on Form 8-K and Amendment
     No. 1 to Current Report on Form 8-K, filed with the Commission on February
     7, 1997 and February 26, 1997, respectively, Arthur Andersen, London,
     England, resigned as auditors of The Cronos Group, a Luxembourg Corporation
     headquartered in Orchard Lea, England (The "Parent Company"), on February
     3, 1997.

     The Parent Company is the indirect corporate parent of CCC, the General
     Partner of the Registrant. In its letter of resignation to the Parent
     Company, Arthur Andersen stated that it resigned as auditors of the Parent
     Company and all other entities affiliated with the Parent Company. While
     its letter of resignation was not addressed to CCC, Arthur Andersen
     confirmed to CCC that its resignation as auditors of the entities referred
     to in its letter of resignation included its resignation as auditors of CCC
     and the Registrant.

     CCC does not believe, based upon the information currently available to it,
     that Arthur Andersen's resignation was triggered by any concern over the
     accounting policies and procedures followed by the Registrant.

     Arthur Andersen's report on the financial statements of CCC and the
     Registrant, for years preceding 1996, has not contained an adverse opinion
     or a disclaimer of opinion, nor was any such report qualified or modified
     as to uncertainty, audit scope, or accounting principles.

     During the Registrant's 1995 fiscal year and the subsequent interim period
     preceding Arthur Andersen's resignation, there were no disagreements
     between CCC or the Registrant and Arthur Andersen on any matter of
     accounting principles or practices, financial statement disclosure, or
     auditing scope or procedure.

     The Registrant retained a new auditor, Moore Stephens, P.C. on April 10,
     1997, as reported in its Current Report on Form 8-K, filed April 14, 1997.



                                       11
<PAGE>   12
     In connection with its resignation, Arthur Andersen also prepared a report
     pursuant to the provisions of Section 10A(b)(2) of the Securities Exchange
     Act of 1934, as amended, for filing by the Parent Company with the
     Securities and Exchange Commission (the "SEC"). Following the report of
     Arthur Andersen, the SEC, on February 10, 1997, commenced a private
     investigation of the Parent Company for the purpose of investigating the
     matters discussed in such report and related matters. The Registrant does
     not believe that the focus of the SEC's investigation is upon the
     Registrant or CCC. CCC is unable to predict the outcome of the SEC's
     ongoing private investigation of the Parent Company.

     In 1993, the Parent Company negotiated a credit facility (herinafter, the
     "Credit Facility") with several banks for the use of the Parent Company and
     its affiliates, including CCC. At December 31, 1996, approximately
     $73,500,000 in principal indebtedness was outstanding under the Credit
     Facility. As a party to the Credit Facility, CCC is jointly and severally
     liable for the repayment of all principal and interest owed under the
     Credit Facility. The obligations of CCC, and the five other subsidiaries of
     the Parent Company that are borrowers under the Credit Facility, are
     guaranteed by the Parent Company.

     Following negotiations in 1997 with the banks providing the Credit
     Facility, an Amended and Restated Credit Agreement was executed in June
     1997, subject to various actions being taken by the Parent Company and its
     subsidiaries, primarily relating to the provision of additional collateral.
     This Agreement was further amended in July 1997 and the provisions of the
     Agreement and its Amendment converted the facility to a term loan, payable
     in installments, with a final maturity date of May 31, 1998. At December
     31, 1997, approximately $37,600,000 was outstanding under the Credit
     Facility.

     The terms of the Agreement and its Amendment also provide for additional
     security over shares in the subsidiary of the Parent Company that owns the
     head office of the Parent Company's container leasing operations. They also
     provided for the loans to Stefan M. Palatin, the Chairman of the Parent
     Company (the "Chairman") and its Chief Executive Officer (and a Director of
     CCC), of approximately $5,990,000 and $3,700,000 (totaling approximately
     $9,690,000) to be restructured as obligations of the Chairman to another
     subsidiary of the Parent Company. These obligations have been collaterally
     assigned to the lending banks, together with the pledge of 1,000,000 shares
     of the Parent Company's Common Stock owned by the Chairman. These 1,000,000
     shares represent 11% of the issued and outstanding shares of Common Stock
     of the Parent Company as of December 31, 1997. The shares of the Parent
     Company are traded on NASDAQ (CRNSF). (The Chairman, including the
     1,000,000 shares pledged to the banks, owns approximately 55% of the issued
     and outstanding shares of Common Stock of the Parent Company as of December
     31, 1997). Additionally, CCC granted the lending banks a security interest
     in the fees to which it is entitled for the services it renders to the
     container leasing partnerships of which it acts as general partner,
     including its fee income payable by the Registrant.

     The lending banks have indicated that they will not renew the Credit
     Facility, and the Parent Company has yet to secure a source for repayment
     of the balance due under the Credit Facility at May 31, 1998. CCC is
     currently in discussions with the management of the Parent Company to
     provide assurance that the management of the container leasing partnerships
     managed by CCC, including the Registrant, is not disrupted pending a
     refinancing or reorganization of the indebtedness of the Parent Company and
     its affiliates.

     The Registrant is not a borrower under the Credit Facility, and neither the
     containers nor the other assets of the Registrant have been pledged as
     collateral under the Credit Facility.

     The Registrant is unable to determine the impact, if any, these concerns
     may have on the future operating results and financial condition of the
     Registrant or CCC and the Leasing Company's ability to manage the
     Registrant's fleet in subsequent periods.



                                       12
<PAGE>   13
     Year 2000

     The Registrant relies upon the financial and operational systems provided
     by the Leasing company and its affiliates, as well as the systems provided
     by other independent third parties to service the three primary areas of
     its business: investor processing/maintenance; container leasing/asset
     tracking; and accounting finance. The Registrant has received confirmation
     from its third-party investor processing/maintenance vendor that their
     system is Year 2000 compliant. The Registrant does not expect a material
     increase in it vendor servicing fee to reimburse Year 2000 costs. Container
     leasing/asset tracking and accounting/finance services are provided to the
     Registrant by CCC and its affiliate, Cronos Containers Limited (the
     "Leasing Company"), pursuant to the respective Limited Partnership
     Agreement and Leasing Agent Agreement. CCC and the Leasing Company have
     initiated a program to prepare their systems and applications for the Year
     2000. Preliminary studies indicate that testing, conversion and upgrading
     of system applications is expected to cost CCC and the Leasing Company less
     than $500,000. Pursuant to the Limited Partnership Agreement, CCC or the
     Leasing Company, may not seek reimbursement of data processing costs
     associated with the Year 2000 program. The financial impact of making these
     required system changes is not expected to be material to the Registrant's
     financial position, results of operations or cash flows.

     Cautionary Statement

     This Quarterly Report on Form 10-Q contains statements relating to future
     results of the Registrant, including certain projections and business
     trends, that are "forward-looking statements" as defined in the Private
     Securities Litigation Reform Act of 1995. Actual results may differ
     materially from those projected as a result of certain risks and
     uncertainties, including but not limited to changes in: economic
     conditions; trade policies; demand for and market acceptance of leased
     marine cargo containers; competitive utilization and per-diem rental rate
     pressures; as well as other risks and uncertainties, including but not
     limited to those described in the above discussion of the marine container
     leasing business under Item 2., Management's Discussion and Analysis of
     Financial Condition and Results of Operations; and those detailed from time
     to time in the filings of Registrant with the Securities and Exchange
     Commission.



                                       13
<PAGE>   14
                           PART II - OTHER INFORMATION


Item 6.  Exhibits and Reports on Form 8-K

(a)  Exhibits

<TABLE>
<CAPTION>
        Exhibit
          No.                     Description                        Method of Filing
        -------                   -----------                        ----------------
<S>              <C>                                                 <C>
         3(a)    Limited Partnership Agreement of the                *
                 Registrant, amended and restated as of
                 December 2, 1991

         3(b)    Certificate of Limited Partnership of the           **
                 Registrant

         10      Form of Leasing Agent Agreement with Cronos         ***
                 Containers Limited

         27      Financial Data Schedule                             Filed with this document
</TABLE>


(b)  Reports on Form 8-K

     No reports on Form 8-K were filed by the Registrant during the quarter
ended March 31, 1998.





-------------

*    Incorporated by reference to Exhibit "A" to the Prospectus of the
     Registrant dated December 2, 1991, included as part of Registration
     Statement on Form S-1 (No. 33-42697)

**   Incorporated by reference to Exhibit 3.2 to the Registration Statement on
     Form S-1 (No. 33-42697)

***  Incorporated by reference to Exhibit 10.2 to the Registration Statement on
     Form S-1 (No. 33-42697)



                                       14
<PAGE>   15
                                   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.



                                     IEA INCOME FUND XII, L.P.

                                     By   Cronos Capital Corp.
                                          The General Partner



                                     By    /s/ Dennis J. Tietz
                                          -------------------------------------
                                          Dennis J. Tietz
                                          President and Director of Cronos 
                                          Capital Corp. ("CCC")
                                          Principal Executive Officer of CCC



Date: May 15, 1998



                                       15
<PAGE>   16
                                  EXHIBIT INDEX



<TABLE>
<CAPTION>
        Exhibit
          No.                     Description                        Method of Filing
        --------                  -----------                        ----------------
<S>              <C>                                                 <C>
         3(a)    Limited Partnership Agreement of the                *
                 Registrant, amended and restated as of December
                 2, 1991

         3(b)    Certificate of Limited Partnership of the           **
                 Registrant

         10      Form of Leasing Agent Agreement with Cronos         ***
                 Containers Limited

         27      Financial Data Schedule                             Filed with this document
</TABLE>



-------------

*    Incorporated by reference to Exhibit "A" to the Prospectus of the
     Registrant dated December 2, 1991, included as part of Registration
     Statement on Form S-1 (No. 33-42697)

**   Incorporated by reference to Exhibit 3.2 to the Registration Statement on
     Form S-1 (No. 33-42697)

***  Incorporated by reference to Exhibit 10.2 to the Registration Statement on
     Form S-1 (No. 33-42697)