Introduction. Infantile hemangiomas (IHs) are the most common vascular abnormalities in children under 1 year old; most IHs involute spontaneously and do not need intervention unless a complication occurs. Ulceration and secondary infection are the most common complications. Despite appropriate conventional wound care, ulcerated IHs are difficult to heal. Although oral propranolol and topical timolol have been found to be effective in the treatment of ulcerated hemangiomas, they have been reported to have adverse effects and limitations. Citric acid has been used on pediatric patients without any reported adverse effects in the treatment of a variety of infected wounds refractory to conventional treatment modalities. Herein, the authors report the case of a large, ulcerated, infected hemangioma treated with topical application of citric acid ointment. Case Report. A 6-month-old otherwise healthy infant who had undergone previous, unsuccessful treatment of a large, ulcerated hemangioma infected with Pseudomonas aeruginosa was treated using topical application of 3% citric acid in a petroleum jelly base once daily for 24 days. Topical application of citric acid resulted in complete healing of the ulcer in 24 applications. Conclusions. The efficacy, ease of application, and absence of notable adverse effects of using citric acid suggest it may be an effective option for the treatment of hemangiomas in children.