To provide a contemporary profile of blood pressure and nutritional and sociodemographic relationships in the adult US population, data from the first National Health and Nutrition Examination Survey ( NHANES -I), 1971-1975, were analyzed. Systolic and diastolic blood pressures increased with increasing age, but trends were different by sex and race groups. Body mass index (weight/ height2 ) was the nutritional factor most strongly and consistently related to blood pressure. Among dietary constituents, alcohol consumption and calcium and phosphorus intake were the only variables having consistent and independent relationships to blood pressure. Sodium content of food and salt use had no relationship, and sodium/potassium food content had only an inconsistent association. Regarding serum nutritional measures, serum calcium was directly related and serum phosphorus was inversely related to blood pressure. Serum urate, serum aspartate aminotransferase, and hemoglobin were also independently related to systolic and diastolic blood pressures. There were few important differences by race or sex in these correlates. These observations from a representative sample of the US population have useful implications for prevention and treatment of high blood pressure.