Background. In Peru, cardiovascular disease was the second most common cause of death in those aged 65 years or more in 2000. Hypertension is a major modifiable risk factor for cardiovascular disease, and if treated can significantly reduce cardiovascular disease risk. The objectives of this study were to investigate the prevalence of hypertension and levels of awareness, treatment and control in a deprived urban area of Peru. Methods. A cross-sectional study was completed. Blood pressure measurements were recorded in triplicate. Hypertension was defined as systolic blood pressure ≥ 140 mmHg or diastolic blood pressure 90 mmHg, or self report of receiving antihypertensive medication at the time of interview. Results. The study sample was 584 adults (29.1% male, mean age 35.3 years). Age standardized prevalence of hypertension was 19.5% (95% CI 9.9%, 29.1%) in men, 11.4% (95% CI 3.7%, 19.1%) in women, and 13.2% (95% CI 5.0%, 21.5%) overall. Among those with hypertension 38.3% (95% CI 22.7%, 53.9%, n = 18/47) were aware of their condition with greater awareness among women than men. Of those aware, 61.1% (n = 11/18) were treated, equating to 23.4% (95% CI 10.1%, 36.7%, n = 11/47) of all adults with hypertension. Of those treated 63.6% (n = 7/11) had controlled hypertension, equating to 14.9% (95% CI 3.0%, 26.8%, n = 7/47) of all adults with hypertension. Conclusion. Levels of awareness and control in this population were low. Lack of control is likely to be due to both a failure to diagnose hypertension, especially among men, and initiate or comply with treatment, especially among women. These results suggest a considerable burden of undiagnosed hypertension, and poor levels of control in those treated, in a deprived urban area of Lima, Peru. © 2008 Davies et al; licensee BioMed Central Ltd.