The efficacy and toxicity of intraperitoneal (i.p.) cisplatin plus systemic etoposide were studied in 36 patients with small (< 2 cm) residual i.p. ovarian cancer after achieving a partial response to platinum-based, first-line chemotherapy. Treatment comprised 90 mg/m2 i.p. cisplatin with intravenous (i.v.) sodium thiosulphate (day 1) and 600-800 mg/m2 i.v. etoposide (days 1 and 2), every 4 weeks for four to six cycles. 7 patients achieved a pathological complete response (pCR), one a pathological partial response and 16 were clinically stable without evidence of disease. After a median follow-up of 13 months, the median progression-free survival (PFS) was 11 months (95% confidence interval 7-16 months). The actuarial PFS at 24 months is 22% (95% confidence interval 8-36%). Three of six relapses after achieving a pCR (50%) were sited i.p., and 9 of 14 other patients with disease progression (64%) had an i.p. relapse, indicating insufficient local efficacy. There was no renal toxicity, but grade 3-4 leucopenia occurred in 63% and grade 3-4 thrombocytopenia in 8% of cycles, while nausea, vomiting and complete alopecia were common. Although side-effects were acceptable, the efficacy of treatment with i.p. cisplatin plus i.v. etoposide is limited.