<PAGE>
 
                    U.S. SECURITIES AND EXCHANGE COMMISSION
                            Washington D.C.  20549

                                  FORM 10-QSB

(Mark One)
[X] QUARTERLY REPORT UNDER SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF
    1934


    For the quarterly period ended     March 31, 1999
                                   --------------------------


[_] TRANSITION REPORT UNDER SECTION 13 OR 15(d) OF THE EXCHANGE ACT



    For the transition period from _________________ to _________________


    Commission file number   0-15700
                           ----------------------------------------------


          WINDSOR PARK PROPERTIES 4, A CALIFORNIA LIMITED PARTNERSHIP
   ------------------------------------------------------------------------
       (Exact name of small business issuer as specified in its charter)


           California                                             33-0202608
-------------------------------                              -------------------
(State or other jurisdiction of                              (IRS Employer 
incorporation or organization)                               Identification No.)



           6160 S. Syracuse Way, Greenwood Village, Colorado  80111
--------------------------------------------------------------------------------
                   (Address of principal executive offices)



                                (303) 741-3707
--------------------------------------------------------------------------------
                          (Issuer's telephone number)



Check whether the issuer (1) filed all reports required to be filed by Section
13 or 15(d) of the Exchange Act during the past 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  (_)
     ---         ---

Transitional small business disclosure format (check one): Yes [_]  No [X]
<PAGE>
 
                               TABLE OF CONTENTS

                                    PART I
                                    ------


                                                                           Page
                                                                           ----
 
Item 1.     Financial Statements                                             2

Item 2.     Management's Discussion and Analysis of Financial
            Condition and Results of Operations                              7


                                    PART II
                                    -------


Item 6.     Exhibits and Reports on Form 8-K                                10

            SIGNATURE                                                       11

 
<PAGE>
 
                                     PART I
                                     ------

Certain matters discussed under the Management's Discussion and Analysis of
Financial Condition and Results of Operations and elsewhere in this Quarterly
Report on Form 10-QSB may constitute forward-looking statements for purposes of
Section 21E of the Securities Exchange Act of 1934, as amended, and as such
involve known and unknown risks, uncertainties and other factors which may cause
the actual results, performance or achievements of Windsor Park Properties 4, a
California Limited Partnership, to be materially different from any future
results, performance or achievements expressed or implied by such forward-
looking statements.

                                      -1-
<PAGE>
 
Item 1.   Financial Statements
-------                       




                           WINDSOR PARK PROPERTIES 4
                           -------------------------
                      (A California Limited Partnership)
                                 BALANCE SHEET
                                 -------------
                                  (unaudited)
<TABLE>
<CAPTION> 
 
                                                                                              March 31, 1999
                                                                                    --------------------------------
ASSETS
------
<S>                                                                                   <C>     
Property held for sale:
  Land                                                                                $                      613,700
  Buildings and improvements                                                                               2,651,500
  Fixtures and equipment                                                                                      77,700
                                                                                    --------------------------------
                                                                                                           3,342,900
Less accumulated depreciation                                                                             (1,669,000)
                                                                                    --------------------------------
                                                                                                           1,673,900
 
Investments in joint ventures and limited partnerships                                                     3,072,400
Cash and cash equivalents                                                                                    448,800
Other assets                                                                                                  21,500
                                                                                    --------------------------------
 
Total Assets                                                                          $                    5,216,600
                                                                                    ================================
 
<CAPTION>  
LIABILITIES AND PARTNERS' EQUITY
--------------------------------
<S>                                                                                   <C>      
Liabilities:
  Due to General Partners and affiliates                                                                      26,300
  Accrued expenses                                                                                            79,100
  Tenant deposits and other liabilities                                                                       16,200
                                                                                    --------------------------------
 
Total Liabilities                                                                                            121,600
                                                                                    --------------------------------
 
Partners' equity:
  Limited partners                                                                                         5,097,300
  General partners                                                                                            (2,300)
                                                                                    --------------------------------
 
                                                                                                           5,095,000
                                                                                    --------------------------------
 
Total Liabilities and Partner's Equity                                                $                    5,216,600
                                                                                    ================================
</TABLE>



                See accompanying notes to financial statements.

                                      -2-
<PAGE>
 
                           WINDSOR PARK PROPERTIES 4
                           -------------------------
                      (A California Limited Partnership)
                           STATEMENTS OF OPERATIONS
                           ------------------------
                                  (unaudited)
 
<TABLE>
<CAPTION>

                                                                             Three Months Ended March 31,
                                                              ------------------------------------------------------------
 
                                                                          1999                            1998
                                                              ----------------------------     ---------------------------
<S>                                                             <C>                              <C>           
REVENUES
--------
Rent and utilities                                               $                 154,500       $                 296,100
Equity in earnings of joint ventures and limited partnerships                       32,000                          42,700
Interest                                                                             4,100                           8,600
Other                                                                                2,200                          11,000
                                                              ----------------------------     ---------------------------
 
                                                                                   192,800                         358,400
                                                              ----------------------------     ---------------------------
<CAPTION> 
COSTS AND EXPENSES
------------------
<S>                                                             <C>                              <C>            
Property operating                                                                  61,600                         176,800
Depreciation and amortization                                                       34,000                          59,900
Interest                                                                                 0                          43,100
General and administrative:
  Related parties                                                                    4,200                          10,400
  Other                                                                             16,600                          15,200
                                                              ----------------------------     ---------------------------
 
                                                                                   116,400                         305,400
                                                              ----------------------------     ---------------------------
 
Net income                                                       $                  76,400       $                  53,000
                                                              ============================     ===========================
 
Net income - general partners                                    $                     800       $                     500
                                                              ============================     ===========================
 
Net income - limited partners                                    $                  75,600       $                  52,500
                                                              ============================     ===========================
 
Basic and Dilutive earnings per limited partnership unit         $                     .39       $                    0.27
                                                              ============================     ===========================
</TABLE>



                 See accompanying notes to financial statements

                                      -3-
<PAGE>
 
                           WINDSOR PARK PROPERTIES 4
                           -------------------------
                      (A California Limited Partnership)
                           STATEMENTS OF CASH FLOWS
                           ------------------------
                                  (unaudited)

<TABLE>
<CAPTION>
                                                                 Three Months Ended March 31,
                                                    ------------------------------------------------------
                                                              1999                          1998
                                                    ------------------------      ------------------------
<S>                                                   <C>                           <C>          
Cash flows from operating activities:
  Net income                                           $              76,400        $               53,000
  Adjustments to reconcile net income to net cash
  provided by operating activities:
    Depreciation and amortization                                     34,000                        59,900
    Equity in earnings of joint ventures and limited
      Partnerships                                                   (32,000)                      (42,700)
    Joint ventures' and limited partnerships cash
      Distributions                                                   32,000                        42,700
    Amortization of deferred financing costs                               0                         3,300
 
    Changes in operating assets and liabilities:
      Other assets                                                    (4,900)                       40,800
      Accounts payable                                                  (800)                      (21,100)
      Due to General Partners and affiliates                           5,700                          (900)
      Accrued expenses                                                15,100                        46,400
      Tenant deposits and other liabilities                              200                             0
                                                    ------------------------      ------------------------
Net cash provided by operating activities                            125,700                        99,800
                                                    ------------------------      ------------------------
 
Cash flows from investing activities:
  Investment in joint venture and limited
   partnerships                                                            0                           (50)
  Joint ventures'and limited partnerships cash
    Distributions                                                     32,400                       123,050
  Increase in property held for investment/sale                      (25,000)                            0
                                                    ------------------------      ------------------------
 
Net cash provided by (used in) investing activities                    7,400                       123,000
                                                    ------------------------      ------------------------
 
Cash flows from financing activities:
  Cash distributions                                                (219,900)                     (220,200)
                                                    ------------------------      ------------------------
 
Net cash used in financing activities                               (219,900)                     (220,200)
                                                    ------------------------      ------------------------
 
Net increase (decrease) in cash and cash equivalents                 (86,800)                        2,600
 
Cash and cash equivalents at beginning of period                     535,600                       561,400
                                                    ------------------------      ------------------------
 
Cash and cash equivalents at end of period             $             448,800        $              564,000
                                                    ========================      ========================
</TABLE>



                See accompanying notes to financial statements.

                                      -4-
<PAGE>
 
                           WINDSOR PARK PROPERTIES 4
                           -------------------------
                      (A California Limited Partnership)
                         NOTES TO FINANCIAL STATEMENTS
                         -----------------------------
 
NOTE 1.  THE PARTNERSHIP
         ---------------

Windsor Park Properties 4, A California Limited Partnership (the "Partnership"),
was formed in June 1986 for the purpose of acquiring and holding existing
manufactured home communities for investment.  The General Partners of the
Partnership are The Windsor Corporation ("TWC"), a California corporation, and
John A. Coseo, Jr. In September 1997, Chateau Communities, Inc., a publicly held
real estate investment trust ("Chateau"), purchased 100 percent of the shares of
The Windsor Corporation.  The Partnership was funded through a public offering
of 200,000 limited partnership units at $100 per unit, which commenced in
September 1986 and terminated in September 1987.

In accordance with the Partnership's Agreement of Limited Partnership, the term
of the Partnership expired on December 31, 1997 and, unless the term of the
Partnership is extended, the General Partners are obligated to take actions to
liquidate and dissolve the Partnership.  Accordingly, in the fourth quarter of
1997, the General Partners began to develop a plan to liquidate the Partnership.
The first phase of such plan of liquidation involved the Partnership's marketing
of its Sunrise Village property, a wholly-owned property, and Harmony Ranch
property, a partially-owned property, for sale.  As a result, the Partnership
sold the Sunrise Village Property for approximately $1.7 million to a third
party in May 1998.  The second phase of such plan of liquidation involved the
sale by the Partnership of its remaining assets not sold to third parties to
N'Tandem Trust, an externally-advised California business trust in which
Chateau, as of March 31, 1999, held 17% of the outstanding common stock
("N'Tandem").  Accordingly, the Partnership and N'Tandem have proposed a
transaction whereby the Partnership would sell its single remaining wholly-owned
property and its six partially-owned properties to N'Tandem.  The consummation
of the proposed transaction with N'Tandem is subject to the satisfaction of
certain conditions, including the approval of a majority of the Partnership's
limited partners.  If the proposed transaction with N'Tandem is consummated, the
Partnership will be liquidated and dissolved and liquidating distributions will
be made to limited partners in accordance with the terms of the Partnership's
Agreement of Limited Partnership.

The general partners anticipate that all of the Partnership's properties and
ownership interests in properties will be sold on or before June 30, 1999.

NOTE 2.  BASIS OF PRESENTATION
         ---------------------

The balance sheet at March 31, 1999 and the related statements of operations for
the three months ended March 31, 1999 and 1998 and the statements of cash flows
for the three months ended March 31, 1999 and 1998 are unaudited.  However, in
the opinion of the general partners, they contain all adjustments, of a normal
recurring nature, necessary for a fair presentation of such financial
statements.  Interim results are not necessarily indicative of results for a
full year.

The financial statements and notes are presented as permitted by Form 10-QSB and
do not contain certain information included in the Partnership's annual
financial statements and notes on Form 10-KSB for the year ended December 31,
1998.

                                      -5-
<PAGE>
 
NOTE 3.  INVESTMENTS IN JOINT VENTURES AND LIMITED PARTNERSHIPS
         ------------------------------------------------------

The Partnership's investments in joint ventures and limited partnership consist
of interests in six manufactured home communities at March 31, 1999.  The
combined condensed results of operations of the joint venture and limited
partnership properties for the three months ended March 31, 1999 and 1998 are as
follows:

<TABLE>
<CAPTION>
                                                  1999                       1998
<S>                                    <C>                         <C>
   Total revenues                      $               878,800     $              896,800
   Expenses:
   Property operating                                  408,800                    406,100
   Interest                                            211,000                    239,900
   Depreciation                                        182,600                    174,900
   General and administrative                            3,800                      5,000
                                     -------------------------   ------------------------
 
                                                       806,200                    825,900
                                     -------------------------   ------------------------
 
   Net income                          $                72,600     $               70,900
                                     =========================   ========================
</TABLE>

NOTE 4.  BASIC AND DILUTIVE EARNINGS PER LIMITED PARTNERSHIP UNIT
         --------------------------------------------------------

Basic and dilutive earnings per limited partnership unit is calculated based on
the weighted average number of limited partnership units outstanding during the
period and the net income allocated to the Limited Partners.  The weighted
average number of limited partnership units outstanding during the three months
ended March 31, 1999  and 1998 was 195,266 and 195,461 respectively.

NOTE 5.  DISTRIBUTIONS TO LIMITED PARTNERS
         ---------------------------------

Distributions to limited partners in excess of net income allocated to limited
partners are considered a return of capital.  A breakdown of cash distributions
to limited partners for the three months ended March 31, 1999 and 1998 follows:

<TABLE>
<CAPTION>
                                                        1999                                         1998
                                     ------------------------------------------   ------------------------------------------
                                                                            Per                                         Per 
                                                       Amount               Unit                   Amount               Unit   
                                                       ------               ----                   ------               ----
<S>                                  <C>                       <C>                <C>                       <C>       
Net income  - limited partners       $                 75,600  $             .39  $                52,500  $            0.27
Return of capital                                     142,000                .72                  171,500               0.88
                                     ------------------------  -----------------  -----------------------  -----------------
 
                                     $                217,600  $            1.11  $               224,000  $            1.15
                                     ========================  =================  =======================  =================
</TABLE>

                                      -6-
<PAGE>
 
Item 2.
-------

               MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
               -------------------------------------------------
                      CONDITION AND RESULTS OF OPERATIONS
                      -----------------------------------
                                        
Three months ended March 31, 1999 as compared to three months ended March 31,
-----------------------------------------------------------------------------
1998
----

The following discussion should be read in conjunction with the financial
statements and Notes thereto included elsewhere in this Form 10-QSB.

Expiration of Term of Partnership
---------------------------------

In accordance with the Partnership's Agreement of Limited Partnership, the term
of the Partnership expired on December 31, 1997 and, unless the term of the
Partnership is extended, the General Partners are obligated to take actions to
liquidate and dissolve the Partnership.  Accordingly, in the fourth quarter of
1997, the General Partners began to develop a plan to liquidate the Partnership.
The first phase of such plan of liquidation involved the Partnership's marketing
of its Sunrise Village property, a wholly-owned property, and Harmony Ranch
property, a partially-owned property, for sale.  As a result, the Partnership
sold the Sunrise Village Property to a third party in May 1998.  The second
phase of such plan of liquidation involved the sale by the Partnership of its
remaining assets not sold to third parties to N'Tandem.  Accordingly, the
Partnership and N'Tandem have proposed a transaction whereby the Partnership
would sell its single remaining wholly-owned property and its six partially-
owned properties to N'Tandem.  The consummation of the proposed transaction with
N'Tandem is subject to the satisfaction of certain conditions, including the
approval of a majority of the Partnership's limited partners.

The General Partners anticipate that all of the Partnership's properties and
ownership interests in properties will be sold on or before June 30, 1999.

Results of Operations
---------------------

The results of operations for the three months ended March 31, 1999 and 1998 are
not directly comparable due to the sale of Sunrise Village in May 1998.  The
Partnership recognized net income of $76,400 and $53,000 for the three months
ended March 31, 1999 and 1998, respectively.  Net income per limited partnership
unit was $0.39 in 1999 and $0.27 in 1998.

Rent and utilities revenues decreased from $296,100 in 1998 to $154,500 in 1999,
due to the sale of Sunrise Village.

Equity in earnings of joint ventures and limited partnerships represents the
Partnership's share of the net income of six manufactured home communities.
Equity in earnings of joint ventures and limited partnerships decreased from
$42,700 in 1998 to $32,000 in 1999 primarily due to a reduction in net income at
Big Country due to lower occupancy and increased utility expenses.

Property operating expenses decreased from $176,800 in 1998 to $61,500 in 1999
due to the sale of Sunrise Village.

Interest expense decreased from $43,100 in 1998 due to the payoff of the
Partnership's mortgage debt associated with the sale of Sunrise Village.

General and administrative expense decreased from $25,600 in 1998 to $20,800 in
1999 due mainly to lower employee time charges.

                                      -7-
<PAGE>
 
Liquidity and Capital Resources
-------------------------------

The Partnership's primary sources of cash during the three months ended March
31, 1999 were from the operations of its investment properties and distributions
from joint ventures.  The primary uses of cash during the same period were for
debt service and cash distributions to partners.

No further investment property acquisitions are planned by the General Partners.

At March 31, 1999 the Partnership's total mortgage debt, including its
proportionate share of joint venture and limited partnership debt, was
$3,367,400, consisting of $900,000 of fixed rate debt and $2,467,400 of variable
rate debt.  The average rate of interest on the fixed and variable rate debt was
8.9% and 8.75%, respectively at March 31, 1999.

The future sources of cash for the Partnership will be provided from property
operations, cash reserves, and the sales of property.  The future uses of cash
will be for Partnership administration, capital expenditures, cash distributions
to partners and debt service.  The General Partners believe that the future
sources of cash are sufficient to meet the working capital requirements of the
Partnership for the foreseeable future.

Inflation
---------

All of the leases or terms of tenants' occupancies at the properties allow for
at least annual rental adjustments.  In addition, all of the leases are month-
to-month and enable the Partnership to seek market rentals upon reletting the
sites.  Such leases generally minimize the risk to the Partnership of any
adverse effect of inflation.

Year 2000 Compliance
--------------------

The general partners have assessed the impact of the year 2000 issue on its
reporting systems and operations.  The year 2000 issue exists because many
computer systems and applications abbreviate dates by eliminating the first two
digits of the year, assuming that these two digits are always "19".  As a
result, date-sensitive computer programs may recognize a date using "00" as the
year 1900 rather than the year 2000.  Unless corrected, the potential exists for
computer system failures or incorrect processing of financial and operational
information, which could disrupt operations.

Substantially all of the computer systems and applications and operating systems
in use in use by the Windsor Corporation and the properties have been, or are in
the process of being upgraded and modified. The Partnership is of the opinion
that, in connection with those upgrades and modifications, it has addressed
applicable year 2000 issues as they might affect the computer systems and
applications located in the Partnership's offices and properties. The
Partnership anticipates that implementation of solutions to any year 2000 issue
which it may discover will require the expenditure of sums which the Partnership
does not expect to be material.

The Partnership is exposed to the risk that one or more of its vendors or
service providers may experience year 2000 problems which impact the ability of
such vendor or service provider to provide goods and services.  Due to the
availability of alternative suppliers, this is not considered as significant a
risk with respect to the suppliers of goods.  The disruption of certain
services, however, such as utilities, could, depending upon the extent of the
disruption, have a material adverse impact on the Partnership's operations.  To
date, the Partnership is not aware of any vendor or service provider year 2000
issue that management believes would have a material adverse impact on the
Partnership's operations.  The Partnership, however, has no means of ensuring
that its vendors or service providers will be year 2000 ready.  The inability of
vendors or service providers to complete the year 2000 resolution process in a
timely fashion could have an adverse impact on the Partnership and the effect of
non-compliance by vendors or service providers is not determinable at this time.
Residents who pay rent to the Partnership do not pose year 2000 problems for the
Partnership given the type and nature of the Partnership's properties and
residents.

                                      -8-
<PAGE>
 
Widespread disruptions in the national or international economy, including
disruptions affecting the financial markets, resulting from year 2000 issues, or
in certain industries, such as commercial or investment banks, could also have
an adverse impact

Management expects to have all systems appropriately modified before any
significant processing malfunctions could occur and does not expect the year
2000 issue will materially impact the financial condition or operations of the
Partnership.

                                      -9-
<PAGE>
 
                                    PART II
                                    -------


Item 6.  EXHIBITS AND REPORTS ON FORM 8-K
         --------------------------------

         (a)  Exhibits and Index of Exhibits

              (3)  Certificate and Agreement of Limited Partnership filed as
                   Exhibit A to Registration Statement No. 33-6812 and
                   incorporated herein by reference.

              (27) Financial Data Schedule

         (b)  Reports on Form 8-K
 
              None
 

                                      -10-
<PAGE>
 
                                   SIGNATURE



In accordance with the requirements of the Exchange Act, the registrant caused
this report to be signed on its behalf by the undersigned, thereunto duly
authorized.


                                        WINDSOR PARK PROPERTIES 4,
                                        A California Limited Partnership
 
 
                                        By:  The Windsor Corporation, 
                                             its General Partner



                                        By  /s/ Steven G. Waite
                                            --------------------------------
                                            STEVEN G. WAITE
                                            President
 
Date:  May 7, 1999

                                      -11-