Adenocarcinoma of the lung (ACL) attracts increasing attention because of the fast rising incidence. Systemic chemotherapy with cytostatic agents has been widely used for patients with inoperable ACL, but a standard treatment has not yet been defined. A review of the literature revealed that the highest response rates observed for single agents and combination chemotherapy in ACL in randomized studies were 22% and 38%, respectively, while the longest median survivals were 35 weeks and 34 weeks. Independent prognostic factors for survival in ACL patients were performance status, prior non-radical resection, liver metastases, white blood cell count and serum values of lactate dehydrogenase and aspartic aminotransaminase. Using logistic regression analysis, the only significant predictor of response was measurable disease parameter, while 26 other variables were not significant. Response to chemotherapy was not a major prognostic factor for survival, probably because of the low rate of complete responses (4%). Chemotherapy in ACL remains experimental and the prognosis for these patients is poor. High priority should therefore be given to the identification of new agents or combination regimens with appreciable activity. The knowledge of prognostic factors should be used for optimal design of trials and interpretation of the results.