To test whether alternating chemotherapy is a favorable treatment modality in small-cell lung cancer (SCLC), 334 patients were randomized to receive either fixed cyclic-alternating treatment with ifosfamide/etoposide (IE), cyclophosphamide, doxorubicin, and vincristine (CAV), or response-oriented treatment with IE therapy up to maximal response and subsequently an immediate switch to CAV. In both arms, six cycles were given in 3-week intervals. After chemotherapy, patients with limited-stage disease received chest irradiation with 45 Gy. Prophylactic cranial irradiation with 30 Gy was applied to all complete responders. No maintenance therapy was given to patients with complete response. Minimum follow-up was 2 years. Of 321 assessable patients, the overall response rate was 70% for cyclic alternating and 77% for response-oriented treatment. Complete remission (CR) rates were 26% versus 26%. The median survival times were 9.7 months for cyclic-alternating versus 10.7 months for response-oriented treatment; the 2-year survival rates were 11% versus 9%. In limited-stage disease (LD) patients, there was a median survival of 12.5 months versus 12.3 months and a 2-year survival rate of 21% versus 18%. In extensive-stage disease (ED) patients, median survival was 8.5 versus 9.1 months, and the 2-year survival rate 3% versus 4%. From these results, we conclude that the cyclic-alternating treatment according to the hypothesis of Goldie et al has no advantage in comparison to a sequential treatment strategy with an immediate switch to a second-line protocol at the time no further response to first-line therapy is seen. Our major aim in the treatment of SCLC is to administer an active regimen at any time during the course of treatment regardless of whether sequential or alternating therapy is used.