The Gynecological Cancer Intergroup (GCIG) has previously reached consensus regarding the criteria that should be used in clinical trial protocols to define progression-free survival after first-line therapy as well as the criteria to define response to treatment in recurrent disease using the serum marker CA 125 and has specified the situations where these criteria should be used. However, the publications did not include detailed definitions, nor were they written to accommodate the new version of Response Evaluation Criteria In Solid Tumors (RECIST) criteria (version 1.1) now available. Thus, we recommend that the definitions described later in detail are incorporated into clinical trial protocols to maintain consistency. The criteria for defining progression are now acceptable in clinical trials of recurrent disease as they have since been validated (Pujade-Lauraine, personal communication, 2010). The GCIG requests that data from all clinical trials using these definitions are made available to GCIG trial centers so that continual validation and improvement can be accomplished. These definitions were developed from analyzing patients receiving cytotoxic chemotherapy and have not yet been validated in patients receiving molecular targeting agents.