A phase II study of prolonged oral etoposide at 50 mg m-2 was performed in patients with refractory ovarian cancer. A dose schedule algorithm was used to generate a calendar with the number of capsules to be administered each day and the date of blood tests. Fourteen of 15 patients were evaluable for response. Among the evaluable patients, 12 (86%) had poorly differentiated tumors, 13 (93%) had primary or secondary platin-resistant tumors, and 12 (86%) had progressed on a prior taxoid therapy. The median number of prior regimens was four (1-7). Despite the use of a 50-mg capsule of etoposide, the algorithm permitted the delivery of a median of 94% (89-107.5%) of the ideal calculated dose. The dose-limiting toxicity was myelosuppression with a grade 3 or 4 neutropenia in two-thirds of the patients. There were no deaths on the study and no significant neurologic or cardiovascular toxicity noted. There were no objective responses. The median survival of evaluable patients was 8.1 (95% CI 5.6-13.2) months.