A total of 18 patients with locally advanced (Stage III) adenocarcinoma and large cell undifferentiated carcinoma of the lung, previously untreated, were enrolled in a Phase II trial. Treatment consisted of carboplatin 325 mg/m2, day 1 and etoposide 100 mg/m2 on days 2 and 3. All patients were evaluable for response. Of these, one patient had a partial response (5.5%; confidence interval 0-24%). Toxicity comprised mainly leukopenia and anaemia. Other toxicities were mild. This Phase II study evidenced a poor response rate for these regimes on adenocarcinoma and large cell undifferentiated carcinoma of the lung.