A 41-year-old woman with no known immunosuppression experienced a 12-year period of a relapsing phaeohyphomycosis. Despite administration of multiple courses of therapy with standard antifungals, sustained clinical remission was not achieved. A partial response was seen initially with the combination of itraconazole and flucytosine therapy, but the patient did not respond to subsequent treatment. During the patient's pregnancy, the mycosis became disseminated, with lymphadenopathy and fever, and was considered life threatening. Despite receipt of parenteral amphotericin B therapy, the patient did not show a clinical response. After premature delivery by cesarean section, treatment with oral posaconazole suspension (800 mg/day) was started. The patient's condition improved within 1 week after initiating treatment; therapy was continued for 13 months. During posaconazole treatment, the patient showed a complete clinical response, with negative results of fungal cultures.