OBJECTIVE To investigate whether renal dysfunction induced by cadmium is related to plasma anti-metallothionein antibody (anti-MT Ab) in workers occupationally exposed to cadmium. METHODS The male workers in a smeltery were selected as the subjects for the exposure and effect assessment. The urine cadmium (UCd), the blood cadmium (BCd) and the occupational cadmium intake (TTCd) served as the exposure indexes while the urine beta(2) microglobulin (Ubeta(2)-MG), the N-acetyl-beta-D-glucosaminidase (UNAG) and the urine albumin concentration (UALB) served as the effect markers for the renal dysfunction caused by the cadmium. The titer of the plasma anti-metallothionein antibody was determined with the enzyme linked immunosorbent assay (ELISA). RESULTS The UCd (3.16 microg/g Cr), BCd (9.28 microg/L), Ubeta(2)-MG (81.17 microg/g Cr) and UALB (7.03 mg/g Cr) in the occupational cadmium exposure group were significantly higher than those in the control group and the Ubeta(2)-MG, UNAG and UALB as well as the occurrence rate of abnormality would be increased with the increase of the level of the occupational cadmium exposure. There was no significant difference in the titer of anti-MT Ab between the exposure group and the control group (P > 0.05). The titer of the anti-MT Ab would not be increased with the increase of the dosage of the exposure and had no significant correlation with BCd, UCd and TTCd (P > 0.05). The positive correlation were found between anti-MT Ab and UNAG as well as between anti-MT Ab and Ubeta(2)-MG in the exposure group with the correlation coefficient of 0.302 and 0.218 respectively. The workers with high level anti-MT Ab are more susceptible to cadmium nephrotoxicity than those with low anti-MT Ab with the odds ratio (OR) value of 4.200 and the 95% CI between 1.213 and 14.541 (P < 0.05). CONCLUSIONS There is a dose-effect relationship between cadmium exposure and renal dysfunction in workers occupationally exposed to cadmium, but no correlation is found between cadmium exposure and plasma anti-MT Ab. The workers occupationally exposed to the cadmium with higher level of anti-MT Ab are easier to suffer from renal dysfunction caused by cadmium. Plasma anti-MT Ab could be used as a biomarker of susceptibility in the workers exposed to cadmium.