To investigate the role of body composition (body weight, fat distribution and weight change over time) in ethnic differences in the incidence of hypertension in an ethnic Dutch, South Asian Surinamese and African Surinamese background population living in the Netherlands.We included 361 participants without hypertension at baseline (147 ethnic Dutch, 82 South Asian Surinamese, 132 African Surinamese), aged 35-60 years, in whom anthropometric measurements and blood pressures were measured at baseline and after mean 9 years of follow-up. Data were analysed using logistic regression analyses, with hypertension at follow up as a dependent variable.Body weight, fat distribution and weight gain were positively associated with the risk of developing hypertension; these associations did not statistically significantly differ between ethnic groups [odds ratios (ORs), 95% confidence interval (95% CI) per SD: BMI 1.5 (1.2-2.0); waist circumference 1.5 (1.2-1.9); waist to hip ratio (WHR) 1.4 (1.1-1.9), weight gain of 1-2.9 kg/m 1.8 (0.9-3.8)]. As compared with Dutch, a higher incidence of hypertension was found among South Asian Surinamese [OR 2.6 (1.4-4.8)] and in particular among African Surinamese [OR 3.1 (1.76-5.30)]. Among South Asian Surinamese, adjustment for WHR attenuated the OR the most [OR 1.9 (1.0-3.7)]; among African Surinamese, the strongest effect was observed for adjustment by BMI and WHR simultaneously [OR 2.5 (1.4-4.4)].The ethnic differences in the incidence of hypertension among a middle-aged group with a Dutch, South Asian Surinamese and African Surinamese background were partly explained by body composition. This suggests that other factors may be involved, including genetic factors or unidentified other determinants.