People with metabolic syndrome (MS) are at increased risk of coronary heart disease and other health problems, such as diabetes and stroke. However, there is little previous information on the prevalence and determinants of MS among people with intellectual disabilities (IDs). The present study aimed to examine the prevalence of MS risk factors among institutionalized adults with IDs. We analyzed the annual health check data of 164 institutionalized adults with IDs whose age was [greater than or equal] 20 years in 2009. The measure of MS in the study was the presence of three or more of the following five components: central obesity, elevated blood pressure (BP), elevated fasting glucose (FG), elevated triglycerides (TG), and reduced high-density lipoprotein (HDL-C). The prevalence of MS was 11.6% in the study participants (8% in males and 17.2% in females), which is lower than that in the general population of Taiwan. In the logistic regression analysis of the occurrence of MS, we found that gender, TG and HDL-C were variables that could significantly predict MS after controlling for other potential factors. Adults with IDs who were female (OR = 38.354, 95% CI = 1.985-741.029) and who had higher TG levels (OR = 1.043, 95% CI = 1.008-1.079) and reduced HDL-C levels (OR = 0.696, 95% CI = 0.549-0.883) had a statistically higher risk of MS. This study was one of the first to provide information on the prevalence of MS and its risk factors among institutionalized adults with IDs. We suggest that further study should focus on the specifics of MS, such as incidence, age-specific risk factors and further prevention or treatment in people with ID. (Contains 1 figure and 7 tables.)