An epidemic of acute histoplasmosis occurred in a long-established residential neighborhood in central Illinois. Ten of the 28 individuals living in the five duplex buildings comprising the housing project had evidence of acute infection. The epidemic was unusual in that the infections apparently occurred as the result of adults tending their gardens and children playing under and about the tress of the area. No specific event, such as a construction project or the demolishing of an old building, was involved as a point source, as has usually been observed in past epidemics. The infections occurred sporadically over a summer and probably resulted from exposure to any one of several sites where the fungal organisms were shown to exist in the housing area.