The prevalence and risk factors of hypertension vary in ethnic groups. This study aimed to estimate the hypertension prevalence and to compare risk factors associated with hypertension in women of four ethnic groups in Taiwan. The study subjects were participants in the Taiwanese Survey on Hypertension, Hyperglycemia and Hyperlipidemia (TwSHHH) enrolled in 2002. In this analysis, only 2810 women who were at age of 20-80 years old and whose father and mother had same ethnic background (Minnan, Hakka, Aborigines or Mainland Chinese) were included. Results showed that there were significant ethnic differences in the prevalence of hypertension, obesity indices, fasting glucose, dyslipidaemia, hyperuricaemia, history of alcohol drinking and tobacco smoking and socioeconomic status. Aborigines had the highest prevalence of hypertension (28.6%) and diabetes mellitus (8.9%), whereas the Minnan group had the second highest prevalence of hypertension (19.2%) and diabetes mellitus (7.9%). Both age and central obesity were associated with an increased prevalence of hypertension except central obesity in Mainland Chinese in all four ethnic groups. Compared with the Mainland Chinese as the referent, the multivariateadjusted odds ratio (OR) (95% CI) was 1.19 (0.63-2.26), 1.92 (1.15-3.21) and 2.03 (1.00-4.12) for Hakka, Minnan and Aborigines, respectively. Elevated body mass index (X27.0 vs o24.0 kg m À2 ) and central obesity were significantly associated with hypertension showing multivariate-adjusted OR (95% CI) of 1.68 (1.18-2.38) and 1.95 (1.48-2.57), respectively. In addition, dyslipidaemia, hyperuricaemia and diabetes associated with higher OR for hypertension in Minnan women. In conclusion, there were ethnic variations in hypertension prevalence and determinants in Taiwanese women.