Thyroid hormone has been reported to affect renal function. To investigate the effects of thyroid hormone on the progression of renal deterioration, thyroid hormone (dried thyroid) and an antithyroid drug (thiamazole) were administered to adriamycin (ADR)-induced renal failure rats. The rats were divided into four groups, including 1) ADR-DT, given dried thyroid and thiamazole; 2) ADR-T, given thiamazole; 3) ADR; and 4) control. The survival rate at the end of the study (22 weeks) was 62.5% in ADR-DT group and 100% in ADR-T, ADR, and control groups, respectively. There was a significant difference in the body weight and pulse rate between ADR-DT and ADR-T or ADR groups, except for the pulse rate at week 6 (P<0.05). The creatinine clearance was greater in the ADR-T group than in the ADR or ADR-DT groups at week 22, and was significantly different between the ADR-T and the ADR-DT groups (P<0.05). The fractional kidney weight and tubular changes were significantly greater in the ADR-DT group than in the ADR-T or ADR groups (P<0.05). The interstitial volume was significantly greater in the ADR-DT group than in the ADR-T group (P<0.05). We therefore conclude that a dried thyroid has an aggravative effect in the tubular changes and relative interstitial volume induced by ADR.