This article investigates the prevalence of metabolic syndrome (MS) and the benefits of lowered body mass index (BMI) cutoff point for assessing MS prevalence in a large, nationally representative population sample comprising of 15,365 Thai adults from metropolitan Bangkok who received annual checkup. Prevalence of MS was characterized using the International Diabetes Federation criteria and BMI ≥ 25 kg/m(2) as cutoff revealed that 26.63% of male and 14.90% of female subjects had MS and the prevalence was age dependent. Traditional BMI cutoff of ≥ 30 kg/m(2) underestimated MS prevalence in Thai population while BMI ≥ 25 kg/m(2) was found to be a suitable solution. Common combinations of MS components were identified in order to find common occurrences that may be implicated in the development of diabetes and/or cardiovascular diseases.