Abstract Carboplatin was evaluated in a Phase I and pharmacokinetic study at the Royal Marsden Hospital between April 1981 and November 1981. Sixty patients were entered of whom 16 had impaired renal function. No evidence of ototoxicity or nephrotoxicity was found. Nausea and vomiting were much reduced compared to cisplatin. The dose limiting toxicity was delayed myelosuppression with thrombocytopenia being more severe than leucopenia. A number of clinical responses were seen, particularly in patients with ovarian carcinoma. Pharmacokinetic studies suggested that the dose of JM8 should be adjusted according to the glomerular filtration rate.