To evaluate risk factors for primary brain tumors, a case-control study was carried out with all death certificates and corresponding occupational histories of males registered in the Brazilian Navy Insurance from 1991 to 1995. Cases were 40 individuals with ICD-9 codes 191, 192.1, and 192.0 (brain and CNS tumors). Controls were 671 subjects who had other reported cancer sites. Men less than 56 years of age (odds ratio, OR = 4.63; 95% confidence interval, CI: 2.54, 8.45) and unmarried men (OR = 3.18; 95% CI: 1.69, 5.99) had higher mortality from brain tumors. After adjustment of age, marital status, and socioeconomic status, more brain tumors were found among health personnel (OR = 2.13; 95% CI: 1.07, 4.97) than in other occupational categories. Infantry servicemen engaged in combat training had borderline excess brain tumor mortality (OR = 2.30; 95% CI: 0.89, 5.99). More detailed occupational data on exposures and potential confounders are necessary to improve research on occupational risk factors.