Histoplasma capsulatum was recovered from the pooled homogenate suspension of lungs, liver, and spleen of six of 50 (12%) Mexican free-tailed bats collected from a western Oklahoma cave. All isolates formed characteristic tuberculate macroconidia and small pyriform microconidia. All were converted to typical yeast forms when subcultured under appropriate conditions of growth. Incubation time necessary for culture of the fungus from infected tissue varied from 21 to 43 days, and the number of viable organisms recovered from each pool of organs ranged from one to 24. These recoveries establish the existence of the natural infection of bats in Oklahoma.