We designed an intensive, weekly treatment regimen for patients with small-cell lung cancer (SCLC) using six of the most active chemotherapeutic agents for this disease (doxorubicin [DOX], cyclophosphamide [CTX], vincristine [VCR], etoposide [VP-16], cisplatin [CDDP], and methotrexate [MTX]). The goal of this program was to gain rapid, repetitive exposure to multiple, active drugs. Treatment was administered weekly for a total of 16 weeks. Seventy-six SCLC patients (limited disease, 34; extensive disease, 42) were treated. The overall complete plus partial response rate was 82%. Complete response rates of 47% and 38% were observed in patients with limited (LD) and extensive disease (ED), respectively. The median survivals for patients with LD and ED were 16.6 and 11.4 months, respectively. Toxicities were tolerable and were primarily hematologic. Twenty-six patients had one or more transient life-threatening toxicities, but only one patient developed a fatal toxicity. Eighty-four percent of the patients received 80% or greater of the intended protocol dosages over the entire 16-week treatment period. We conclude that this intensive, short-duration treatment regimen is at least as good as other "standard" regimens, and we are encouraged aged by the complete response rate and median survival in patients with ED SCLC.