Aims &Objectives : 1) To study the serum thyroid stimulating hormone (TSH) levels in 100 females regular menstrual cycle control group & 100 females patients with menorrhagia.  2) To compare the serum TSH levels in 100 regular menstrual cycle control group & 100 patients with menorrhagia.  Materials&Methods : The present study is a cross–sectional observational study with comparison group & has been carried out in Dept. of Biochemistry, GMC, Nagpur from Feb. 2015 to Nov. 2016.  A total of 100 patients with menorrhagia aged between 20 – 45 years were selected from the Obs. & Gyn. OPD of GMC, Nagpur & 100 normal healthy females of same age group 20 – 45 years were selected as controls after satisfying all inclusion & exclusion criterias, ethical committee approval & willing to give consent. Serum TSH levels was estimated by one step non competitive immunoenzymatic sandwich ELISA assay using ERBA thyrokit TSH kit.  The samples were analyzed by Robonik readwell touch Elisa plate analyzer & Robonik Washwell plate ELISA washer.  Results : The results presented in the table indicates that mean TSH levels were significantly raised (>3.45 μIU/ml) in 23 patients as compared to 11 controls.  Discussion : Prevalence of thyroid dysfunction was higher in females patients with menorrhagia as compared to the normal menstrual cycle females control group & we found that the commonest type of uterine bleeding pattern seen in overt & subclinical hypothyroidism cases was menorrhagia.