Increased left ventricular mass (LVM) and lower socioeconomic status (SES) are predictors of cardiovascular morbidity and mortality. Blacks and Hispanics are more likely to have higher LVM and lower SES. The relation between SES, race-ethnicity, and LVM has not been fully explored. Data were used from the NOMAS population-based sample of 1916 subjects living in Northern Manhattan. SES was characterized on the basis of educational attainment and divided into 4 categories. Echocardiography-defined LVM was indexed according to height at the allometric power of 2.7 and analyzed as a continuous variable. LVM varied by race in our cohort (blacks 48.9 g/m2.7, Hispanics 48.4 g/m2.7, whites 45.6 g/m2.7; P=0.004). Using ANCOVA, there was a significant inverse and graded association between mean LVM and SES for the total cohort. Mean LVM was 48.4 g/m2.7, 48.6 g/m2.7, 47.1 g/m2.7, and 45.3 g/m2.7 for the lowest to the highest educational level category (P trend=0.0004). This relationship remained among normotensives (P trend=0.0005) and was present for blacks (P trend=0.009), but not for whites (P trend=0.86) or Hispanics (P trend=0.47). The difference in mean LVM between the highest and lowest categories of education was 5.3 g/m2.7 for blacks, 0.0 g/m2.7 for whites, and 1.0 g/m2.7 for Hispanics. Lower SES is an independent predictor of increased LVM among hypertensive and normotensive blacks.