To investigate the relationship between community-level socioeconomic factors and the incidence of gang-related homicide in the city of Los Angeles. An ecological group-level analysis was conducted to correlate the 5-year incidence rates (from 1988 through 1992) of gang-related homicide with community-level socioeconomic statistics for the 18 geographically distinct Los Angeles Police Department divisions. Eight socioeconomic factors were examined: (1) log mean per capita income, (2) proportion employed, (3) proportion high school graduates, (4) proportion single-parent families, (5) proportion male, (6) proportion younger than 20 years of age, (7) proportion African American, and (8) proportion Hispanic. Pearson correlation coefficients were calculated for the interrelationships among the study variables and gang-related homicide. Adjusted regression estimates were calculated from a multiple linear regression model. The overall 5-year gang-related homicide rate for the city was 48.8 per 100,000, with a range of 5.2 to 173.5 per 100,000 among the different Los Angeles Police Department divisions. Pearson correlation coefficients revealed that the strongest negative correlations with gang-related homicide were log mean per capita income and proportion employed, and the strongest positive correlations were proportion single-parent families and proportion younger than 20 years of age. With mutual adjustment of all variables, only log mean per capita income and proportion employed were significantly associated with gang-related homicide. At the community level, gang-related homicide in Los Angeles is most closely associated with lower income and unemployment. These relationships may provide important insights into the causes of gang formation and gang violence.