BACKGROUND AND OBJECTIVES: DUB accounts for 10% of all gynecology related complaints. This study is to evaluate the thyroid function in patients having abnormal menstrual bleeding from puberty to premenopausal age groups which is interesting and justifiable and will help in further management of DUB and also know the prevalence of hypothyroidism in patients provisionally diagnosed as DUB. The objectives are to evaluate and detect the thyroid dysfunction in patients with dysfunctional uterine bleeding (all age groups), especially in menorrhagic patients and to refer positive cases to the physician for further treatment of thyroid disorder. METHODS: This study is carried out in the department of Obstetrics and Gynecology, AIMS, B G Nagara on 100 women who were clinically given the provisional diagnosis of DUB. All these patients were subjected to routine investigations and T3, T4 & TSH estimation and were grouped as euthyroid, subclinical hypothyroid, hypothyroid or hyperthyroid. RESULTS: Out of the 100 patients taken into study 11 had thyroid disorders, out of which subclinical hypothyroidism was most prevalent accounting for 8 cases, 2 cases were found to have hypothyroidism and 1 case of hyperthyroidism was detected. INTERPRETATION AND CONCLUSION: There is a high prevalence of thyroid disorder in cases which are clinically diagnosed as DUB. Hence the biochemical evaluation of T3, T4, TSH is extremely important and valuable in detecting these patients. Unnecessary surgery was avoided in 11% of patients and they were treated medically which was more accurate and cost effective. Hence thyroid function evaluation should be made mandatory in cases of DUB to detect thyroid dysfunction.