A high level of sodium (440 mg/L) in the water supply of Gila Bend, Ariz, caused concern because of apparently elevated rates of hypertension in Gila Bend Papago Indians. We surveyed 342 Gila Bend Papago Indians and 375 non-Indians from July to September 1983. Participants 25 years of age and older were interviewed for health risk factors, water consumption, and dietary sodium and calcium intake and had height, weight, blood pressure, and urinary sodium and potassium levels measured. No consistent associations were found between any of the sodium values and systolic or diastolic blood pressure. Mean blood pressures for the Gila Bend whites were lower in most age groups than in comparison US white populations. The prevalence rates of hypertension in Gila Bend were not significantly higher than national rates.