Fifty patients with chronic renal insufficiency underwent clinical evaluation & studies of thyroid function the results were compared with age & sex-matched controls. (20%) of patients had biochemical hypothyroidism with low serum T3, T4, & high serum TSH. All the members of the control group were biochemically euthyroid. The mean values of serum T3, T4 were significantly lower & mean serum TSH was significantly higher as compared to controls. There was no correlation of thyroid functions with decrease in renal function. To conclude thyroid dysfunction occurs both clinically & biochemically in patients with chronic renal insufficiency.