Background: Hypothyroidism is the most common endocrine disorders. Musculoskeletal and renal dysfunctions are often observed in cases of hypothyroidism anytime during the disease process. Aims & Objectives: To determine the influence of thyroid hormones on creatine kinase (CK) activity and serum creatinine levels in hypothyroid patients and to determine the extent of musculoskeletal and renal involvement. Materials and Methods: Serum T3 , T4 , TSH, Total CK activity and S. Creatinine levels were estimated. Results and Conclusion: The rise in total CK activity in hypothyroidism can be either due to increased leakage from muscles, increased turnover of muscle proteins or can be due to decreased clearance from the circulation. Increased serum creatinine level, decreased GFR and decline in creatinine clearance were obvious in overt hypothyroidism. The elevation in serum creatinine levels in hypothyroidism can be due to skeletal muscle dysfunction with associated renal involvement