- Purpose: To determine the risk factors during perinatal and first year postnatal period that associated with metabolic syndrome in adolescent Method: We invited in 2184 adolescents whose mothers during 1989-1990 had participated in a study of birth weight and nutrition during pregnancy. In this present study, history, physical exam and blood sampling were collected to determine whether participants have metabolic syndrome. We analysed the association between the perinatal-postnatal risk factors and metabolic syndrome. The risk factors included the history of the small for gestational, history of rapid growth in weight during the first year of life and the amount of maternal diet during pregnancy. The Local Research Ethics Committee approved the study and participants gave written consent. Result: 623 patients agreed to participate in the present study. 291 patients were males and the mean age was 20 years old. There were 35 patients with MS. We found the history of SGA was not associated with MS, but the history of rapid growth of weight during first year was associated with MS (p=0.038). The percentage of MS in patients with history of rapid growth and slow growth was 12.2% and 4.2% respectively (odd ratio 3.17; 95% confidence interval 0.83-11.59) Conclusion: Our study found SGA was not associated with MS, but the history of rapid growth was associated with MS. The postnatal nutrition appear to be important to determine the health of people in long terms.