In this study, renal function of 52 workers of a primary lead smelter located in Northeast Brazil was compared to a reference group of 44 otherwise similar workers of a paper mill. Renal dysfunction, defined by a serum creatinine level ≥ 1.5 mg/dl, was found in 17 (32.7%) workers at the lead smelter, the exposed group, but in only 1 (2.3%) individual from the reference group. Workers from the exposed group also showed significantly higher mean serum uric acid levels. Renal dysfunction of workers from the exposed group was statistically associated with duration of the employment at the smelter and with age, but not with the levels of lead and zinc protoporphyrin in blood and δ-aminolevulinic acid in urine. The two groups presented similar rates of arterial hypertension. However, arterial hypertension was much more strongly associated with renal dysfunction in the lead worke