We describe a North American human immunodeficiency virus (HIV)-positive patient with Strongyloides stercoralis infection of the gastrointestinal tract, who required repeated "standard" courses of thiabendazole. Pulmonary infection with numerous roundworms developed, as suspected by bronchoalveolar lavage, and while he was receiving therapy, dissemination occurred. On autopsy, S stercoralis was recovered in the gastrointestinal tract, liver, lung, and heart. After a literature review, we conclude that HIV-positive patients have a higher risk of dissemination and "standard" treatment failure. This may occur without elevation of IgE or eosinophilia. Those patients may require prolonged courses of thiabendazole or alternatively ivermectin therapy.