WINTHROP
REALTY TRUST  
FORM 10-Q SEPTEMBER 30, 2006

Exhibit 31.1

CERTIFICATION

I, Michael L.
Ashner, certify that:

| | 1. | I
have reviewed this Quarterly Report on Form 10-Q of  Winthrop Realty Trust;
| | -- | -----------------------------------------------------------------------------

| | 2. | Based
on my knowledge,  this report does not contain any untrue statement of a material fact or
omit to state a material  fact necessary to make the statements  made, in light of the
circumstances  under which such  statements were made, not  misleading with respect to
the period covered by this report;
| | -- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | 3. | Based
on my  knowledge,  the financial  statements,  and other  financial  information
included in this report,  fairly  present in all material respects the financial
condition,  results of operations and cash flows of the Registrant as of,  and for, the
periods presented in this report;
| | -- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | 4. | The
Registrants  other certifying  officer and I are responsible for establishing and
maintaining  disclosure  controls  and procedures (as defined in Exchange Act Rules
13a-15(e) and 15d-15(e)) for the Registrant and have:
| | -- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (a) | Designed
such  disclosure  controls and  procedures,  or caused such  disclosure  controls and
procedures to be  designed under our supervision,  to ensure that material information
relating to the registrant,  including its  consolidated subsidiaries, is made known to
us by others within those entities,  particularly during the period  in which this report
is being prepared;
| | --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (b) | Designed
such internal  control over  financial  reporting,  or caused such  internal  control
over  financial  reporting to be designed under our supervision,  to provide reasonable
assurance  regarding the reliability of  financial  reporting and the  preparation  of
financial  statements  for external  purposes in accordance  with  generally accepted
accounting principles;
| | --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (c) | Evaluated
the  effectiveness  of the  Registrants  disclosure  controls and  procedures  and
presented in this  report our conclusions about the effectiveness of the disclosure
controls and procedures,  as of the end of the  period covered by this report based on
such evaluation; and
| | --- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (d) | Disclosed
in this report any changes in the  Registrants  internal  control  over  financial
reporting  that  occurred during the Registrants  most recent fiscal quarter,  that
has materially  affected,  or is reasonably  likely to materially affect, the Registrants
internal control over financial reporting; and
| | --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | 5. | The
Registrants other certifying officer and I have disclosed,  based on our most
recent evaluation of internal control  over financial  reporting,  to the Registrants
auditors and the audit committee of the Registrants board of directors  (or persons
performing the equivalent functions):
| | -- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

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WINTHROP
REALTY TRUST  
FORM 10-Q SEPTEMBER 30, 2006

| | (a) | All
significant  deficiencies  and material  weaknesses  in the design or  operation of
internal  control over  financial  reporting  which are  reasonably  likely to  adversely
affect the  Registrants  ability to record,  process, summarize and report
financial information; and
| | --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (b) | Any
fraud, whether or not material,  that involves management or other employees who have a
significant role in  the Registrants internal control over financial reporting.
| | --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|Date: October 27, 2006 | /s/Michael L. Ashner                      
|---------------------- | ------------------------------------------
|                       |                                           
|                       | Michael L. Ashner 
Chief Executive Officer

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