The cadmium concentration of renal tissue from 82 patients who had died at the age of 45-65 years has been determined by atomic absorption spectrophotometry; 43 were normotensive and 39 hypertensive. Renal cadmium concentration was higher in normotensives than in hypertensives. When smoking habits were taken into account, renal cadmium concentration was found to be 82% higher in normotensives than in hypertensives. Other workers have found the opposite relationship. It is proposed that this discrepancy might reflect either that variations due to age were not taken into account in previous investigations or that a difference exists between soft-water areas and hard-water areas such as the one studied.