Multivariate analysis was performed on 1,336 patients with lung cancer to determine the prognostic significance of stage, race, gender, age, and treatment in each histologic subtype. The study was designed to establish a subgroup of patients whose survival outcome might be better, based on these factors. On univariate analysis, stage and surgery were significant factors in each histologic subtype. The presence of liver metastases, was an important prognostic factor in all subtypes except large cell carcinoma. However, 131 of 140 patients with large cell carcinoma had liver metastases, and this factor may account for the observation that liver metastases was not a significant prognostic factor. In the multivariate analysis, good prognosis was associated with early stage disease and surgical treatment in all cell types. For a given stage, the improvements in relative risk due to surgery represent both the effect of treatment and the effects of other unmeasured patient characteristics, such as performance status and physiological status, that make the patient a suitable candidate for surgery.