The use of topical metronidazole has been limited to the treatment of acne rosacea, infected foot ulcers associated with diabetes mellitus, varicose veins, postirradiation ulcers, and dental conditions since the Food and Drug Administration approved the drug in 1988. Because of this agent's apparent effectiveness in treating anaerobic bacterial infections in such ulcers, the authors believed that treatment of arterial insufficiency ulcers with a solution of topical metronidazole would be a rational approach. They describe a 30-year-old man in whom bilateral lower extremity cellulitis developed as a result of arterial insufficiency. The patient's ulcers were unresponsive to intravenously administered antibiotics and whirlpool therapy. However, when a topical solution of metronidazole was administered, the ulcers began to heal and epithelialization at the ulcer sites occurred. The authors review others' studies concerning clinical use of topical metronidazole and suggest that further study is warranted. To the authors' knowledge, topical metronidazole solution for the treatment of arterial insufficiency and venous stasis ulcers has not been previously reported.