We have evaluated the prognostic value of 22 pretreatment attributes in 436 small cell lung cancer (SCLC) patients included in a prospective multicenter study with a minimum 5-year follow-up. Pretreatment clinical and laboratory parameters were registered. Possible prognostic factors were evaluated by univariate analysis (log rank test) and by the Cox multivariate regression model. In the univariate analysis of all patients, only age, nodal metastasis, and skin metastasis were not associated with survival. The multivariate Cox model identified gender, extent of disease, performance status (PS), weight loss, platelet count, LDH, and NSE as independent prognostic factors. In subset multivariate analyses according to extent of disease, we found haemoglobin level, PS, NSE, and total WBC as significant prognostic indicators for survival in limited-stage disease (LD-SCLC), while PS, weight loss, LDH, number of metastases, liver metastases, and brain metastases were identified as independent prognostic factors in extensive-stage disease (ED-SCLC). There was a significant correlation between serum LDH and NSE levels. In conclusion, gender, extent of disease, PS, weight loss, haemoglobin, WBC count, platelet count, LDH, and NSE were all found to be independent prognostic factors for SCLC survival. However, the prognostic value of these factors depends highly on whether all or subsets of SCLC patients are studied.