Hypertension is more common among persons with non-insulin-dependent diabetes mellitus than among appropriately matched nondiabetic populations. The presence of hypertension in persons with non-insulin-dependent diabetes mellitus is associated with increased rates of the microvascular and macrovascular complications of non-insulin-dependent diabetes mellitus. A cross-sectional study of a cohort of 817 diabetic Navajo Indians was performed to determine the age-, sex-, and duration-specific prevalence of diagnosed hypertension. Persons with end-stage renal disease were excluded from the population. A total of 388 of the patients (47.5%) had diagnosed hypertension. The prevalence of hypertension increased with increasing age. Contrary to findings in other populations, women did not have higher rates of hypertension than men. The duration of diabetes did not have a consistent effect on the rates of hypertension. The current prevalence of hypertension among Navajos with diabetes is higher than that reported two decades ago.