Background: This study accounted for the prevalence of metabolic syndrome and its determinants in rural areas of Thai Binh Province, Vietnam. Methods: The study was conducted in 2012 through a multi-stage (province-district-commune) stratified cluster random sampling to choose a representative sample of non-institutionalized adults from four communes in Thai Binh Province. A structured questionnaire was administered, collecting information on personal medical history, demographic, and behavioral characteristics. Anthropometrics, blood pressure, and venous blood samples were obtained. Metabolic syndrome (MetS) was defined according to three operational definitions. The prevalence ratios and their respective 95% confidence intervals were calculated. Results: The prevalence rates of metabolic syndrome in this sample of adults were 19.6. As expected, participants with MetS had significantly higher mean values of weight, body mass index, and waist circumference. The prevalence of metabolic syndrome was significantly higher in women (p ˂ 0.001) and older participants (p ˂ 0.001), as well as in those who reported hypertension (p ˂ 0.001) or dyslipidemia (p ˂ 0.001). Conclusions: This study showed that metabolic syndrome is highly prevalent in the Vietnamese adult population. As age increases and base metabolism and mobility decrease, obesity rates and risk factors for MetS appear to increase.