This epidemiological study was designed to evaluate the prevalence of undetected hypertension in an apparently healthy western Indian population having no history of major illness. 3629 individuals of 18 years of age were included in the study. Hypertension (HTN) was defined as systolic blood pressure (SBP) 140 mmHg or diastolic blood pressure (DBP) ≥ 90 mmHg and prehypertension (PHTN) as SBP ≥ 120–139 mmHg or DBP ≥ 80–89 mmHg, but without HTN. The prevalence of undiagnosed HTN in the total population was 26% and was 11% and 40% in the young ( 40-year) and old ( 40-year) populations, respectively. The prevalence of PHTN, 40% in the overall population, was nearly the same in the young (39%) and the old population (42%). The risk factor most strongly associated with PHTN and HTN was obesity, showing the highest odds ratio in the overall (PHTN 2.14; 95% CI 1.20–3.81; HTN 2.72; 95% CI 1.53–4.85), the young (PHTN 2.29; 95% CI 1.25–4.21; HTN 2.92; 95% CI 1.59–5.35), and the old (PHTN 1.13; 95% CI 0.65–1.96; HTN 1.38; 95% CI 0.79–2.4) populations. Hypertension is a major risk factor for cardiovascular diseases which must not be ignored, especially in the western Indian population.