The role of cis-dichlorodiammineplatinum(II) (cis-platinum) as a single agent in non-small cell lung cancer has not been clearly defined, and extensive phase II studies have not been conducted. However, objective responses were noted in several early clinical trials. A review of these reports, including combinations with conventional agents, shows 15 partial responses among 100 patients. Results are presented on a new protocol using high-dose cis-platinum with mannitol-induced diuresis combined with cyclophosphamide and Adriamycin. An overall partial response rate of 28% was observed, including a 38% response rate in good performance status patients, with a median survival of 16 months in responding patients. Data from recent combination protocols do not define the activity of cis-platinum as a single agent, but suggest that it may be useful in non-small cell carcinoma of the lung.