Acral ulcers in patients with progressive systemic sclerosis (PSS) are often recalcitrant to therapy. Sildenafil, an inhibitor of phosphodiesterase-5, dilates small arteries by increasing endothelial cGMP. Oral administration of sildenafil to a 35-year-old white male patient suffering from incapacitating PSS with severe pulmonary arterial hypertension and acral ulcers induced a clinically significant reduction in dyspnea and increase in walking distance within one week as well as complete and long-lasting healing of all ulcers within five weeks. This case demonstrates the efficacy of sildenafil in the treatment of scleroderma-associated refractory acral ulcers.