Objectives: To estimate the prevalence and characteristics of metabolic syndrome (MS) in persons living in Long An province. Methods: cross sectional descriptive study on 1408 persons more than 19 years old living in Long An province in 2010. Results: The prevalence of metabolic syndrome by IDF, NCEP ATP III and updated NCEP ATP III were 10.4 percent, 12.4 percent and 17.2 percent respectively. MS gradually increases with age group from 6.2 percent in the 20-39 until age group or = 60 with 33.5 percent. Women (40.7 percent) with MS was higher than men (20.0 percent in females, 13.5 percent in men). The most common factor was dyslipidemia. Conclusions: The prevalence of MS by IDF, NCEP ATP III and updated NCEP ATP III were 10.4 percent, 12.4 percent and 17.2 percent respectively, MS gradually increases with age group, in females higher than in men. Most of metabolic syndrome is dyslipidemia.