The FONICAP group is screening, with randomised phase II studies, the activity of new chemotherapy programmes for advanced non-small-cell lung cancer (NSCLC) looking for regimens with > 30% activity. In the present study, three regimens were tested: MIP (mitomycin 6 mg m-2, ifosfamide 3 g m-2, cisplatinum 80 mg m-2 on day 1 every 28 days); MIP-IFN (MIP and interferon alpha-2b 3 MU s.c. three times a week); and PC (cisplatinum 60 mg m-2 and carboplatin 400 mg m-2 on day 1 every 28 days). Overall 93 chemotherapy-naive patients were enrolled: 23 received MIP, 27 received MIP-IFN and 43 received PC. Eighty per cent of the patients had stage IV and 20% stage IIIb disease (positive pleural effusion or supraclavicular nodes). Response rates were as follows: MIP = 9% (95% CI 1-28%), MIP-IFN = 7% (95% CI 1-24%) and PC = 14% (95% CI 5-28%). The overall median survival was 183 days. Grade III-IV leucopenia was observed in 36% of patients treated with MIP-IFN vs 10% in the other two arms, and thrombocytopenia grade III-IV was reported in nearly 10% of patients overall. In conclusion, (1) all three regimens investigated have poor activity (< 30%); (2) when tested in multicentre randomised phase II trials, MIP displays lower activity than in phase II trials; (3) PC has similar activity to other platinum-containing regimens; (4) randomised phase II studies are a reliable and quick method of determining the anti-tumour activity of novel chemotherapeutic regimens in NSCLC.