Systemic therapy with cytostatic agents has been widely used in the management of inoperable adenocarcinoma of the lung (ACL). However, chemotherapy for this tumor type remains experimental, and the prognosis is still poor. Thus, the literature on single-agent chemotherapy was reviewed in order to establish critical background material for the planning and evaluation of future studies. Only vindesine, dibromodulcitol, doxorubicin and hexamethylmelamine have displayed overall response rates exceeding 10% in randomized studies. Several of the most promising agents with response rates above 20% in non-randomized studies, i.e., 5-fluorouracil, mitomycin C, vinblastine and ifosfamide, have not been adequately evaluated in randomized trials in ACL. There is no published evidence to suggest the superiority of single-agent chemotherapy over the best supportive treatment, with respect either to survival or to quality of life. There are considerable methodological problems in designing, executing, analyzing and reporting these studies. Some of the problems could be solved by use of the internationally accepted guidelines for reporting results of cancer treatment, which might make more rapid progress possible.