Treatment response and side effects of venlafaxine were evaluated in an open-label trial of elderly outpatients with dysthymic disorder (DD). Patients received flexible dose (up to 300 mg/d) venlafaxine (Effexor XR) for 12 weeks. Of 23 study patients, 18 completed the trial. Fourteen (60.9%) were responders in intent-to-treat analyses with the last observation carried forward, and 77.8% were responders in completer analyses. Nearly half the sample (47.8%) met criteria for remission. In the intent-to-treat sample, increased severity of depression at baseline was associated with superior response, and the presence of cardiovascular disease was associated with poorer response. Venlafaxine open-label treatment was associated with fairly high response rates and generally good tolerability in elderly patients with DD. These results indicate that in elderly patients with DD, placebo-controlled trials of a dual reuptake inhibitor such as venlafaxine would be needed to assess its efficacy or to compare its efficacy to that of other antidepressants.