The disposition kinetics of the cancer chemotherapeutic agent mitomycin C have been studied in six male patients receiving mitomycin C in combination with cisplatin and vinblastine for non-oat cell carcinoma of the lung. Following rapid IV administration of mitomycin C (10 mg/m2), serum concentration-time course data were biexponential, with biologic half-lives of 46.2 +/- 12.1 min (mean +/- SD). Pharmacokinetic analysis of data by the CSTRIP and NONLIN digital computer programs generated parameters which suggested extensive distribution (V area = 656.8 +/- 169.8 ml X kg-1, mean +/- SD) and, as reported for other alkylating agents, rapid elimination (total body clearance = 10.3 +/- 3.2 ml X kg-1 X min-1, mean +/- SD). Interpatient variations in pharmacokinetic parameters were relatively small, suggesting that close monitoring of mitomycin C therapy might be unnecessary in patients with normal renal and hepatic function.