Obesity is one of the major risk factors for cardiovascular disease and non-insulin dependent diabetes mellitus. This study describes cigarette smoking and the socio-demographic differences of body fatness in three sub-ethnic distinctive communities in Guangdong Province, China. In this study, 935 adult Chinese (Chauzhou - 203 men and 111 women; Meixian - 169 men and 140 women; Xinhui - 194 men and 118 women) were randomly sampled from three communities. A standard protocol was used to measure stature, body weight, waist and hip circumferences. Body mass index (BMI) and waist-to-hip circumference ratio (WHR) were calculated as measures of total body fatness and abdominal body fatness, respectively. The questionnaire was self-administered and demographic and lifestyle factors were assessed. WHR was positively related to age in men (p=0.0001) and in women (p=0.0001) while BMI was associated with age only in women (p=0.0001). In women, WHR was significantly related to education levels after adjusting for age and BMI (p=0.0300). In men, BMI differed by educational level, after adjusting for age and WHR (p=0.0329). BMI was significantly associated with occupational status in men, after adjusting for age and WHR (p=0.0004). Gross household income was significantly associated with WHR in men, after adjusting for age and BMI (p=0.0469). Male smokers had a significantly lower mean BMI than the non-smokers, after adjusting for age and WHR (p=0.0037). Marital status was not related to body fatness measurements after adjusting for age and WHR. The differences in body fatness in Chinese living in Southern China can not be totally explained by educational level, occupational status, marital status, gross household income and cigarette smoking, particularly in women. Age was the only consistent predictor of abdominal body fatness in both men and women and also of total body fatness in women.