Objective: There is scarcity of literature regarding prevalence and severity of thyroid abnormalities in chronic kidney disease (CKD) patients. This study (i) estimated the prevalence of hypothyroidism in CKD patients, (ii) investigated the effect of thyroid hormone replacement therapy (THRT) on changes in estimated glomerular filtration rate (eGFR) in CKD patients. Material and methods: This was a descriptive longitudinal study conducted in MLB Medical College, Jhansi over a period of 1 year, on patients with CKD. A total of 120 CKD patients with serum creatinine levels available at least two times in previous 6 months were enrolled, screened for thyroid function and those detected with hypothyroidism were treated with L-thyroxine. Before and after treatment, comparisons were made and for statistical analysis, paired t-test was used for association. Results: Out of 120 study subjects, maximum patients were in the age group of 51-60 years (36.67%) with 65% being males and 35% females. Twenty-one (17.5%) were found to have hypothyroidism, 18 (15%) had subclinical hypothyroidism and 3 (2.5%) had overt hypothyroidism. The stage-wise distribution of hypothyroidism in CKD patients was 15.6% in stage III, 16.67% in stage IV and 20% in stage V. The rate of decline in eGFR over 6 months was significantly reduced from 3.05 ± 2.02 mL/min/1.73 m2 before the THRT to 1.02 ± 2.5 mL/min/1.73 m2 after giving thyroid hormone replacement (p < 0.001). Among the patients given thyroid hormone replacement for 6 months, 61.9% showed slower decline in eGFR, 19% showed unchanged decline, 9.5% patients showed a faster decline in eGFR and 9.5% patients showed an improvement in eGFR after THRT. Conclusion: Hypothyroidism (15% subclinical and 2.5% overt) is a relatively common condition in CKD patients. Prevalence of hypothyroidism increased with progressively lower levels of GFR i.e., declining renal function. THRT attenuated the rate of decline in renal function in CKD patients with hypothyroidism, suggesting that THRT may delay reaching end-stage renal disease in these patients.