Socioeconomic status is systematically related to the level of fatness, and therefore the incidence of obesity, in a total community survey of nearly 5,000 adults. Among males with more than 12 years of schooling, the average thickness of 4 fatfolds is 10% greater, amounting to about 2 kg of total fat, than those with 8 years or less of education. In females, however, the opposite trend is observed, those in the higher educational group averaging 20% thinner fatfolds, or about 5.5 kg total fat, than females in the lower educational group. These findings confirm the need for standards of obesity that take socioeconomic status into account.