In the first-line treatment of advanced non-small cell lung cancer (NSCLC), phase II trials of single-agent docetaxel (Taxotere; Rhône-Poulenc Rorer, Antony, France) at a dose of 100 mg/m2 every 3 weeks have reported encouraging results, with an overall response rate of 29% and a median survival duration of 9 months. Neutropenia is the dose-limiting toxicity but, even when severe, is usually of brief duration. Docetaxel also is active against NSCLC at doses of 60 to 75 mg/m2, which are associated with a lower incidence of neutropenia and other side effects. In patients with platinum-treated and refractory disease, docetaxel appears to be the most active chemotherapeutic agent studied to date. In a large multicenter trial of 80 platinum-treated patients, the response rate was 16%, median survival was 7 months, and the 1-year survival rate was 25%. In conclusion, single-agent docetaxel appears to be one of the most active agents in the therapy of advanced NSCLC, with response and survival data in chemonaive patients comparable to that reported for combination chemotherapy regimens and activity in platinum-refractory NSCLC superior to that reported with other agents studied to date. Further studies designed to optimize the therapeutic index of docetaxel and docetaxel-based combination chemotherapy of NSCLC are clearly indicated.