QuickLinks -- Click here to rapidly navigate through this document

Exhibit 10.20

Phase Forward Incorporated

Summary of Cash Compensation Practices for Non-Employee Directors
(Effective January 1, 2005)

Annual retainer for Board membership*:   $10,000
Annual retainer for each standing Board committee membership:
 
$2,000
Additional annual retainer for each standing Board committee chair:
 
$2,000
Board meeting attendance:
 
$1,500 per Board meeting attended in person
$1,000 per Board meeting attended telephonically
Committee meeting attendance:
 
$500 for each standing Board committee meeting attended in person or
telephonically

All meeting fees and a quarterly installment of annual retainer fees are paid in
arrears. In addition, all directors are reimbursed for reasonable out-of-pocket
expenses incurred in attending meetings of the Board of Directors.

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

*To be eligible for the annual retainer for Board membership, Directors are
required to attend at least 75% of the Board meetings by phone or in person, and
at least 50% of the meetings in person. The Company's Chief Financial Officer
may exercise discretion in determining whether certain absences are excusable in
determining whether the attendance thresholds are met.

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

QuickLinks

Summary of Cash Compensation Practices for Non-Employee Directors (Effective
January 1, 2005)