OBJECTIVE : To determine optimal waist circumference cutoff values for predicting metabolic syndrome (MetS) among adults aged 60 years and older in Ecuador. METHODS : The National Survey of Health, Wellbeing, and Aging survey was used to describe the prevalence of MetS according to standard definitions. Receiver operating characteristics (ROC) curve analyses and the Younden index J (YI) were performed to examine optimal waist circumference cutoff values for predicting MetS. Moreover, the prevalence of MetS according to country-specific waist circumference cutoff values was compared with those using standard definitions. RESULTS : Among 2306 participants with a mean age of 70.6 years, the optimal waist circumference cutoff value for predicting MetS was 90.7 cm in women with a sensitivity of 66.1%, specificity of 65.6% and YI of 0.31. In men, a waist circumference of 91.2 cm with a sensitivity of 73.2%, specificity of 62.8%, and YI of 0.36 was the optimal cutoff point for predicting MetS. In general, applying country-specific cutoff values decreased the prevalence of MetS among older Ecuadorian women. In men, except with the ATP III definition, similar MetS prevalence rates were seen whether the country-specific or standard waist circumference cutoff values were applied. CONCLUSIONS : The optimal waist circumference cutoff values for predicting metabolic syndrome among older Ecuadorians adults were 90.7 cm for women and 91.2 cm for men. Moreover, current standard definitions of abdominal obesity may overestimate the prevalence of MetS, particularly in Latin American women.