The authors explored whether the waist circumference (WC) cutoffs currently proposed to define abdominal obesity (AO) are associated with diabetes and cardiovascular disease (CVD) in Latin America. Primary care physicians in 12 countries were randomly chosen to measure WC and body mass index and record the presence of diabetes and CVD in all consecutive adult patients, consulting them on 2 prespecified half-days. Overall, 70% of 9719 men, and 76% of 18,526 women had AO. Diabetes was reported in 10% of men and 9% of women and CVD in 9% of men and 7% of women. AO was significantly related with diabetes (age-adjusted odds ratio, 1.63 for men and 2.86 for women) and with CVD (odds ratio, 1.41 for men and 1.62 for women). Obesity was also significantly related with diabetes and CVD. Strikingly, abdominal adiposity was very frequent in women with normal body mass index, suggesting that an evidence-based definition of abdominal adiposity in Latin America is needed.