Twenty patients with ischemic rest pain were treated with intravenous pentoxifylline, 1,200 mg daily, for up to three weeks. Ten patients obtained sufficient relief to avoid surgical intervention. Seven of these had complete or near complete relief of rest pain, but the other three required continuing analgesia. Transcutaneous oxygen measurements showed a significant increase after the course of treatment. There were marked gastrointestinal side effects in six patients, necessitating early withdrawal from the study. Three of these six patients had shown a favorable response to medication prior to withdrawal. These preliminary results suggest that pentoxifylline may provide a sufficient increase in tissue oxygen availability to avoid, or at least postpone, surgical intervention. A double blind controlled study is required to further assess the efficacy of this drug as an intravenous treatment.