Of 915 resections for bronchogenic carcinoma over a 25-year period (1945-1969), 249 patients survived over 5 years; 127 of the patients eligible survived over 10 years, 61 over 15 years, and 22 over 20 years. The case material was divided into three time periods: 1945-49, 1950-59 and 1960-69, as well as by extent of resection. Lobectomy became the operation of choice, pneumonectomy being reserved for the more extensive lesions. Observed survival rates at 5, 10 and 15 years for 561 patients in the lobetomy series were 35, 22 and 15%, respectively, but strikingly increased to 41, 28 and 19% in the 1960-69 period. Observed rates for 354 patients having pneumonectomies were similar for three time periods, being 16, 8 and 6% at 5, 10 and 15 years, respectively. Relative survival rates for the lobectomy series at 5, 10 and 15 years rose from 33, 28 and 26%, repectively, in the 1950-59 period to 50, 39 and 35% in the last time period, becoming a near horizontal curve segment after 5 years. Dominant factors in survival were extent of the lesion and stage of nodal involvement, histologic type and location being less significant.