This randomized, prospective, placebo-controlled clinical trial compares the influence on nutritional status and survival of hydrazine sulfate with placebo addition to cisplatin-containing combination chemotherapy in patients with unresectable non-small-cell lung cancer (NSCLC). The trial consisted of 65 patients with advanced, unresectable NSCLC who had had no prior chemotherapy, were at least partially ambulatory (Eastern Cooperative Oncology Group [ECOG] performance status [PS] level 0-2), and who had adequate hematologic, renal, and hepatic function. All patients received the same defined combination chemotherapy (cisplatin, vinblastine, and bleomycin) and the same defined dietary counseling with the addition of either three times daily oral hydrazine sulfate (60 mg) or placebo capsules. Hydrazine sulfate compared with placebo addition to chemotherapy resulted in significantly greater caloric intake and albumin maintenance (P less than .05). Considering all patients, survival was greater for the hydrazine sulfate compared with placebo group (median survival, 292 v 187 days), but the difference did not achieve statistical significance. In favorable PS patients (PS 0-1), survival was significantly prolonged (median survival, 328 days v 209 days; P less than .05) for hydrazine sulfate compared with placebo addition. In a multifactor analysis, PS, weight loss, and liver involvement were the final variables. Objective response frequency and toxicity were comparable on both arms. Hydrazine sulfate may favorably influence nutritional status and clinical outcome of patients with NSCLC. Further definitive studies of hydrazine sulfate addition to therapeutic regimens in NSCLC are warranted.