Thyroid diseases increase with age, predominantly affecting women, thus they occur most often in post-menopausal and elderly women.1 There is no consensus on universal screening for thyroid dysfunction in post-menopausal and elderly women worldwide, 2 therefore this study was on thyroid function tests: serum TSH, thyroxine, (T₄), and tri-iodothyronine (T₃) in relation to body mass index (BMI) in post-menopausal women. It was a prospective cross-sectional study of post- menopausal women attending clinics at a Catholic hospital in Benin City, Nigeria. 40 pre-menopausal (control) and 40 post-menopausal healthy women (mean age 31.73±11.45 and 57.06±5.57 years respectively)  were assessed. Informed consent was obtained, a pre- tested structured questionnaire containing their bio-data, gynaecology history and past medical history were obtained, and ethical approval was also obtained. At the end, blood samples were obtained following standard laboratory procedures.3 Results were expressed as mean±SD, analysed using SPSS version 20, and subjected to ‘t-test’ and ANOVA. P< 0.05 was considered statistically significant. Post-menopausal women presented significantly higher (p<0.05) BMI than the control (27.60±4.32 kg/m² vs. 25.42±4.16 kg/m²). Serum TSH levels were significantly higher in post-menopausal than in pre-menopausal women (2.04±0.56 mIU/L vs 0.74±0.11 mIU/L.) Despite the higher TSH, T₃ and T₄ were significantly lower in post-menopausal women (1.02±0.16 ng/ml and 6.07ng/ml) than in pre-menopausal women (4.91±0.43 ng/ml and 10.13±0.25 ng/ml). These findings suggest that there might be reduced T₃ and T₄ receptors in post-menopausal women. The observed increase in BMI in post-menopausal women might be as a result of a fall in BMR, due to the decreased levels of T₃ and T₄.4