The effects of pentoxifylline (Trental) on diabetic neurotrophic foot ulcers was assessed. Twelve insulin-dependent diabetics were evaluated. Each patient had a peripheral neuropathy with secondary neurotrophic ulceration involving the foot. The ulcers were treated using conservative care for at least 3 months prior to entering the patient in the study. During this time, no appreciable decrease in ulcer size was observed. Prior to commencement of the study, the critical closing pressure of the involved foot and the ulcer size were measured and recorded. Six months later these measurements were repeated. Of the 12 patients who started pentoxifylline, nine finished. The remaining three patients completed the study but had discontinued the medication. Of the nine patients finishing the study and taking pentoxifylline, eight ulcers completely healed, with the remaining one having decreased in size. The average critical closing pressure increased 11 mm. Hg. Pentoxifylline appeared to have accelerated the healing process in the nine diabetic ulcer patients.