In a series of 84 various evaluable disseminated cancer patients treated with hydrazine sulfate as a result of a pharmaceutical-sponsored investigational new drug (IND) study, it was found that 59/84 or 70 % of the cases improved subjectively and 14/84 or 17 % improved objectively. Subjective responses included increased appetite with either weight gain or cessation of weight loss, increase in strength and improved performance status and decrease in pain. Objective responses included measurable tumor regression, disappearance of or decrease in neoplastic-associated disorders and long-term (over 1 year) ‘stabilized condition’. Of the overall 59 subjective improvements 25 (42 %) had no concurrent or prior (within 3 months) anticancer therapy of any type. Of the 14 objective improvements 7 (50 %) had no concurrent or prior anticancer therapy. Of the remaining cases in which there was either concurrent or prior anticancer therapy, improvements occurred only after the addition of hydrazine sulfate to the treatment regimen. Duration of improvement was variable, from temporary to long-term and continuing. Side effects were mild, comprising for the most part low incidences of extremity paresthesias, nausea, pruritis and drowsiness; there was no indication of bone marrow depression.