Increased mortality from kidney disease was observed in miners exposed to crystalline silica and elemental mercury (Hg°) in the Idrija Mercury Mine. The objective of this study was to evaluate certain biological markers of potential nephrotoxicity in miners with remote occupational exposure to Hg° and silica dust. 49 ex-miners and 56 age-matched controls were included in the study. The markers of nephrotoxicity were evaluated as a urinary protein of high and low molecular weight (albumin and a1-mglobulin) and N-acetyl-b-D-glucosaminidase enzyme activity (NAG). Past occupational exposure of miners to Hg° was evaluated using biological indices of exposure. The U-Hg levels obtained during past exposure varied from 50 to 122 mg/L. 75% of all observed miners were co-exposed to silica dust. No differences in background exposure to Cd and Pb were observed between the two groups. Slight increases in urinary albumin (p=0.041) and a1-mglobulin (p=0.025) were observed in ex-miners. The magnitude of observed levels of glomerular and tubular proteins represents no clinically significant alteration of renal function. The role of background exposure to Pb and Cd and some other confounders cannot be ruled out.