The population with normal body mass index (BMI) but with abdominal obesity are most of the time the ‘neglected’ population in terms of health interventions. The aim of this study is to study the prevalence of abdominal obesity and to explore the factors causing abdominal obesity by using waist circumference (WC) measurement. A cross sectional study was conducted among a group of respondents in Tanjung Karang, Selangor, Malaysia from January until June 2010, among those aged 18 years old and above, to explore the demographic (gender and ethnics), lifestyle factors (physical activity, carbohydrate intake and smoking status) and measurement of body weight, height and waist circumference. A total of 629 subjects with normal BMI were studied. The prevalence of abdominal obesity was 36.1% based on WC (40.0% males and 70.0% females). The predictor model revealed that being non-Malay (aOR = 2.1; 95% CI: 1.35-3.20) and being female (aOR = 3.6; 95% CI: 2.51-5.06) were the associated factors of having abdominal obesity in normal BMI population. In conclusion, females and non-Malay were factors that were found to be associated with abdominal obesity in normal BMI population. This is important in targeting this vulnerable population with risk factors that can develop non communicable diseases for early interventions.