The generalization that dark-skinned ethnic groups are particularly susceptible to infectious granulomas was tested in a study of 4,989 autopsies performed during a 10-year period in an area where coccidioidomycosis and tuberculosis were both constantly present. Difficulties were encountered in classifying the subjects as to race and also in settling diagnostic questions in cases of arrested or inactive granulomatous lesions, but in persons who died with coccidioidomycosis it was always easy to demonstrate the organisms in the lesions. Acute forms of coccidioidomycosis, with massive suppuration and overwhelming dissemination, occurred in Negroes, Caucasians, and Mexicans; so did the subacute or chronic meningitic forms without obvious visceral involvement. There was evidence that all three groups were living in unfavorable environments. Nevertheless the incidence of fatal disease showed some striking differences. The incidence of fatal coccidioidomycosis was only slightly higher in Mexicans than in Caucasians, but that in Negroes was 10 times as high as in Caucasians. The incidence of fatal tuberculosis was only slightly higher in Negroes than in Caucasians, but in Mexicans it was very much higher. A group of Filipinos living in particularly bad circumstances appeared to be particularly vulnerable to both diseases. The supposed generalization, therefore, did not hold, and it is evidently important to specify which ethnic group and which infectious granuloma is concerned.