We investigated the potential of weekly cisplatin and daily oral etoposide followed by oral etoposide maintenance therapy in patients with platinum-refractory ovarium cancer. One hundred and seven patients were entered on the study, 98 patients completed the induction therapy consisting of cisplatin at either 50 or 70 mg m(-2) weekly for six administrations plus oral etoposide at a dose of 50 mg daily. Of these 98 patients, 38 had a platinum treatment-free interval of more than 12 months, 32 had an interval between 4 and 12 months, and 28 had progressed during or within 4 months after last platinum therapy. We assessed response rates and time to progression, and also response duration and survival. Analyses were done on the 98 evaluable patients. All 107 patients were considered evaluable for toxicity. Of the 38 patients with a treatment-free interval of more than 12 months, 92% responded, with 63% complete responses. The median progression-free survival in these patients was 14 months, and the median survival was 26 months. Of the 32 patients with an interval of 4-12 months, 91% responded, with 31% complete responses, a median progression-free interval of 8 and a median overall survival of 16 months. Of the 28 patients with platinum-refractory disease, 46% as yet responded, with 29% complete responses, median progression-free interval of 5 and an overall survival of 13 months. Haematologic and non-haematologic, particularly renal toxicity and neurotoxicity, were notably mild. We conclude that this intensive regimen of weekly cisplatin plus daily etoposide is highly effective and well tolerated in patients with ovarian cancer relapsing after conventional platinum-based combination chemotherapy, including patients who have progressed during or within 4 months after platinum treatment.