Histoplasmosis is a very rare disease in Korea. Clinical manifestations are very similar to those of tuberculosis. This is the first case report of combined disseminated histoplasmosis and tuberculosis in a patient with HIV infection in Korea. A 42-year-old Korean with Acquired Immunodeficiency Syndrome (AIDS) was diagnosed with tuberculosis. He had lived in Guatemala for the past five years. Upon diagnosis of disseminated tuberculosis with HIV infection, he was treated with anti-tuberculosis medications and anti-retroviral agents. Fever, weakness, hepatosplenomegaly and pancytopenia were persistent despite treatment. The patient's history of living in Guatemala caused us to seek opportunistic infectious organisms other than tuberculosis. Bone marrow aspiration and biopsy were performed and the result revealed numerous intracellular organisms consistent with Histoplasma capsulatum; therefore, the diagnosis of disseminated histoplasmosis was made.