SummaryThe case of a 25 year old man who developed disseminated histoplasmosis following heavy exposure to dust during the process of carrying out renovations to an old home is described. The presenting symptom was an indolent ulcer of the gum margin. Diagnosis was made by the successful culture of Histoplasma capsulatum from the ulcer tissue. This organism was also cultured from soil samples in and near a fowl yard adjacent to his home. It is postulated that this was the source of infection. The disseminated infection resolved within a few weeks following treatment with amphotericin B, but six months later recurrence of infection was evident in the gingival ulcer and the regional submandibular lymph nodes. The affected areas were surgically excised. Twelve months later the patient remains well and apparently free of infection.