We analyzed HIV surveillance data on white, black, and Latino males diagnosed with HIV between 2000 and 2004 in Los Angeles County (LAC) to identify associations between individual- and community-level factors and late HIV detection by race/ethnicity. We defined late HIV detection as an AIDS diagnosis within 6 months of HIV diagnosis. We conducted multilevel analysis to determine individual- and community-level risk factors associated with late HIV detection stratified by race/ethnicity. We mapped HIV-positive males with late HIV detection by race/ethnicity at the zip code level within LAC to determine high burden areas. Overall, 38% of all males met the definition of late HIV detection. By race/ethnicity, 44% of Latinos, 38% of blacks, and 30% of whites were detected late in their course of HIV infection. Latinos and whites had multiple individual-level risk factors associated with late HIV detection. Among black males, only older age at HIV diagnosis was associated with late HIV detection. The only community-level risk factor associated with late HIV detection was among Latinos living in communities with less than 6% of men who have sex with men (proxy for stigma). Mapping the distribution of late HIV detection showed late detection areas generalized across LAC for Latino males in comparison with white and black males whose maps showed clustered areas of late HIV detection. Analysis and mapping of individual- and community-level risk factors associated with late HIV detection provides an important tool for targeting prevention resources to areas and populations with the highest burden of disease.