From 1975 to 1993, 665 patients with non-small cell lung carcinoma (NSCLC) were studied in our Unit. Of the 55 stage IIIA patients submitted to resection, 50 were followed-up in order to evaluate the effectiveness of surgery and to identify which variables had a prognostic impact on survival. The expectancy of survival at 3,5 and 10 years was 31.7, 19.5 and 13.7%, respectively. When the analysis was limited to N2 patients, 3,5- and 10-year survival rates were 20.9, 14 and 7%, respectively. Regarding the "TN" factor, the T3N0 subset presented the highest expected survival (24.8 and 18.6% at 5 and 10 years). With regard to the "T3" factor and type of surgery, peripheral tumors submitted to en bloc resection of the chest wall showed the best 5-year survival rate (42.9%), whereas extrapleural resections--even for tumors confined to the parietal pleura--showed a 5-year survival rate of 14.3%. A slightly higher risk of death was observed in tumors originating in the superior sulcus (SST). No patients with mediastinal pleura and pericardium involvement survived more than 34 months. With univariate analysis, "N2" was the variable most significantly associated with a negative prognosis when related to T3 (T3N2 vs T3N0 0.025 < P < 0.05) or non-epidermoid tumor (no survivors at 3 years; N2 epidermoid vs N2 non-epidermoid tumor P < 0.05). Applying multivariate analysis, epidermoid cell type, even if exclusively for N2 tumors, was an independent prognostic factor, showing a favorable impact on survival expectancy (27.8% at 90 months).