Eighty-one patients with disseminated non-small cell lung cancer (stage IV) were treated with 2 monthly cycles of initial chemotherapy combining cisplatin with vindesine. The initial chemotherapy-responding patients (CR, PR, MR) were randomized to 2 cycles or 4 cycles of maintenance chemotherapy. After initial chemotherapy, the response rate was 33% (CR, PR, MR) with 18.5% objective responses. The overall 1-year survival rate was 15% with 37% for responders as opposed to 2% for non-responders. Maintenance chemotherapy did not improve the response rate obtained after initial cycles. The small number of patients does not allow us to reach a definite conclusion on the optimum duration of maintenance chemotherapy. In the absence of large placebo versus chemotherapy randomized trials, no definite conclusion can be made on the benefit of chemotherapy in disseminated non-small cell lung cancer. This study suggests, however, that chemotherapy is associated with a significantly longer survival in responding patients.