The objective of this study was to examine the prevalence of hypertension and mean blood pressures among Afro-Caribbeans and South-Asians in England compared with Caucasians. Data from the Birmingham Factory Screen, Birmingham INTERSALT volunteers, and four West Midlands churches were combined into a single database (n = 2853), since all three studies employed identical methods. The cohort comprised 2169 (76%) Caucasians (71% men); 453 (16%) Afro-Caribbean (60% men); and 231 (8%) South-Asian men. The results were that overall prevalence of hypertension (> or =160/95 mm Hg or taking antihypertensives) was greater in both Afro-Caribbean men (31%) and women (34%) (both P < 0.001), compared with Caucasians (19% and 13% respectively), while South-Asian men had a similar overall prevalence to Caucasians (16%). Compared with Caucasians, Afro-Caribbeans had significantly higher mean systolic blood pressure, with higher mean diastolic blood pressures evident among Afro-Caribbean women. After adjustment for age, body mass index, smoking, and weekly alcohol intake, the odds ratios (95% CI) for being hypertensive were 1.56 (1.14 to 2.13; P = 0.005) and 2.40 (1.51 to 3.81; P = 0.0002) for Afro-Caribbean men and women, respectively and 1.31 (0.88 to 1.97; P = 0.19) for South-Asian men, compared with Caucasians. In conclusion the prevalence of hypertension and mean blood pressures are higher among Afro-Caribbeans compared with Caucasians. South-Asian men had similar rates of hypertension and mean blood pressures to Caucasians.