This study evaluates the feasibility and acceptability of an online peer support group intervention for women with metastatic breast cancer (MBC). Feasibility, participation rates, participant satisfaction, and preliminary outcomes are examined from a 1999 to 2000 study of online peer support groups for women with MBC. Thirty women with MBC were randomly assigned to either an immediate online support condition or a waitlisted control condition. For practical and ethical reasons, the waitlist period was limited to 2 months. Six monthly assessments were collected using standardized measurement instruments. Intervention retention rates (73%), assessment completion rates (range = 100%-86% in retained participants) and support group participation (M = 5.9 days per week) were high compared to other published studies on this population. Reported satisfaction with the intervention was also high. An online support intervention study is feasible using a waitlist control. Despite the feasibility and acceptability of the study procedures, the study design and small sample size precluded definitive conclusions about intervention effectiveness. As such, study procedures should be replicated with a larger more representative sample to examine the effectiveness of the intervention.