Both hypothyroid (Hypo) and hypozincemia are commonly observed in patients and animals with chronic renal failure (CRF). In CRF whether the hypothyroid plays a role in the pathogenesis of hypozincemia is unclear. This study is designed to investigate the effects of hypothyroid on intestinal zinc absorption and urinary zinc excretion in 5/6 nephrectomized (Nx) rats, because plasma zinc balance is attained through a controlled rate of intestinal uptake as well as renal reabsorption. Intestinal zinc absorption was carried out in jejunum and ileum segments by an in vivo perfusion technique and the renal zinc disposal was evaluated by a conventional method using a standard formula to calculate the zinc tubular reabsorption and the excretion of urinary zinc in 5/6 Nx rats with hypothyroidism. The Hypo-NxT rats showed a significant decrease in the rate of intestinal zinc absorption and in the response of plasma zinc levels during intestinal