Recurrent aphthous stomatitis (RAS) is a common, painful ulcerating condition that affects 20% of healthy individuals. Thalidomide is one of the few drugs found to be effective, but the adverse effect profile limits its usefulness. Pentoxifylline is a drug used in the treatment of peripheral vascular disease. Like thalidomide, it inhibits tumor necrosis factor α production without many of the potential adverse effects. In this randomized, double-blind, placebo-controlled trial, Thornhill et al demonstrated that patients with RAS who took pentoxifylline, 400 mg, 3 times daily had more ulcer-free days, lower median pain scores, and a reduction in median ulcer size, number, and severity, although only the difference with respect to ulcer size reached the level of statistical significance.