The dimorphic fungus Histoplasma capsulatum causes histoplasmosis, an infection that can manifest as anything from a simple, self-limiting illness to a serious, widely spread illness. Fungal culture is still the gold standard for confirmation, but diagnosis is sometimes delayed by its slow development. Bone marrow analysis can offer a quick and accurate diagnostic substitute in these situations. We describe a male immunocompetent patient, age 21, who has had a persistent fever and malaise for three months that have not improved with empirical treatment. Repeated blood cultures and serologic testing came out negative, but laboratory studies showed cytopenias. Grocott-Gomori methenamine silver and periodic acid-Schiff stains, on the other hand, revealed intracellular and extracellular yeast-like organisms in bone marrow aspirate and trephine biopsy that were morphologically consistent with Histoplasma capsulatum.