Analyze racial/ethnic disparities in the prevalence of obesity and its related diseases in Massachusetts and assess disparities in the risk of developing diseases related to overweight and obesity. DESIGN: Cross-sectional analysis of survey data. SETTING: Community-based US population. SUBJECTS: 63,235 non-institutionalized adults in Massachusetts. MAIN OUTCOME MEASURES: BMI, overweight and obesity prevalence and prevalence of obesity-related- diseases, odds of developing obesity-related diseases. Participants were considered hypercholesterolemic, diabetic, hypertensive, or having a cardiovascular disease if they reported that a health professional told them that they had such a disease. Behavioral characteristics of respondents included fruit and vegetable consumption, alcohol drinking, smoking, and physical activity. Demographic variables included sex, age, marital status, employment status, household income, region of residence, and educational status. RESULTS: Blacks (OR = 1.97) and Hispanics (OR = 1.81) had higher odds of obesity as compared to Whites. Blacks had higher odds of high blood pressure (OR = 1.88), heart attack (OR = 1.40) and stroke (OR = 2.14) than Whites. Hispanics were more likely to have high blood pressure (OR = 1.34), high cholesterol (OR = 1.56), stroke (OR = 1.71), and heart attack (OR = 1.54) than Whites. Hispanics (OR = 2.71) and Blacks (OR = 2.58) had the highest odds of diabetes. CONCLUSIONS: Minority groups share a disproportionate risk of obesity and obesity-related diseases. Hispanics and Blacks have significantly higher odds of obesity and its related diseases. Continued emphasis on racial/ethnic groups at greatest risk of obesity remains critical.