Benzaldehyde, in the form of 4,6-benzylidene-alpha-D-glucose (BG), was given iv at a daily dose of 720-1800 mg/m2 to 65 patients with inoperable carcinoma in the advanced stages. The overall objective response rate was 55%; seven patients achieved complete response, 29 achieved partial response, 24 remained stable, and five showed progressive disease. Response was seen in various cell types. Prolongation of survival was apparent for the patients. Toxic reactions were not observed during long-term injection with BG.