We conducted a population survey of cardiovascular risk factors in Kin-Chen, Kinmen (Quemoy), an island under military control for 40 years and the focal point of confrontation between mainland China and Taiwan. During the period 1992-1994, all residents > or = 30 years of age in Kin-Chen, the largest township in Kinmen, were invited to participate. The response rate was 60.3% (3826/6346). The prevalence of hypertension (> or = 160/95 mmHg and/or under treatment) was 25.2% in men and 17.6% in women. The rate for smoking was 41.5% in men and 2.9% in women. The prevalence of diabetes was 6.7% in men and 6.4% in women. Mean values for systolic blood pressure, diastolic blood pressure, total cholesterol, triglyceride, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol were 135.3 mmHg, 85.5 mmHg, 5.3 mmol/l, 1.1 mmol/l, 3.5 mmol/l and 1.4 mmol/l in men; and 128.0 mmHg, 79.5 mmHg, 5.2 mmol/l, 1.0 mmol/l, 3.3 mmol/l and 1.5 mmol/l in women, respectively. The unexpectedly high prevalence of hypertension in Kin-Chen male may reflect the effect of more than 40 years of military control and discipline. The high serum cholesterol level in Kin-Chen relative to mainland China and the low triglyceride level relative to Taiwan and Beijing, suggest further study of the contributions of diet and other psychosocial or environmental factors.