The traditional treatment course for new cases of ovarian, fallopian tube, or peritoneal cancer is cytoreductive surgery followed by chemotherapy with paclitaxel in combination with carboplatin. Unfortunately, despite high initial response rates, the majority of patients recur and subsequent therapy is much less likely to be effective. The use of ineffective chemotherapy can result in unnecessary toxicity and costs, delay of more effective treatment, and the potential for the development of cross-resistance to additional drugs. The ability to individualize therapy by providing the treating physician with ex vivo response information on a panel of drugs should aid in the selection of effective therapy for individual patients, thus resulting in improved outcomes.