Prognostic factors for long term survival were analyzed in a group of 719 patients with small cell lung carcinoma treated within 4 consecutive prospective multicenter trials between 1981 and 1990. 74 patients (10.3%) survived more than 2 years; 30 of them (4.2%) with no evidence of disease. The most significant determinator of prolonged survival was extent of disease: 13.9% (59/424) of patients with limited disease vs. 5.1% (15/295) with extensive disease survived more than 2 years (p < 0.001). Of 138 female patients 24 (17.4%) were long term survivors, compared to 8.6% (50/581) of males (p < 0.01). Initial good performance status and no weight loss were also found to be correlated with long term survival. Of the group of 2-year survivors 51 patients subsequently died (median survival duration 31 months), 10 are alive with cancer or are lost to follow up and 13 are in complete remission with median follow up of 64 months. 20 patients (3.8%) survived more than 5 years. This study confirms the possibility of cure in SCLC, especially in patients with favorable prognostic factors.