A total of 28 previously treated patients with small-cell lung cancer were treated at relapse with 400 mg/m2 carboplatin and 2 mg vincristine on days 1 and 8, every 4 weeks. Ten partial responses (PRs) (37%) but no complete responses (CRs) were seen. Median survival after the start of second-line treatment was 120 days (range, 39-503 days). Toxicity of this regimen was moderate, including WHO grade 3/4 myelosuppression in 26% of courses (n = 66). Eight PRs were seen in a subgroup of 22 patients who relapsed less than 3 months after first-line treatment. The responses seen in this group of patients may be due to the absence of cross-resistance between the regimens used.