Type 2 diabetes mellitus (T2DM) and thyroid disorders (TD) are the two most common endocrine disorders in clinical practice. They show mutually influence on each other. Unrecognized thyroid disorders may adversely affect the metabolic control and add more risk to an already predisposing type 2 diabetes mellitus. The objective of this study was to find out the association of thyroid hormone levels in patients with type 2 diabetes mellitus. This cross sectional study was conducted in the department of Biochemistry and outpatient department of Endocrinology of Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders, Dhaka, Bangladesh (BIRDEM) General Hospital, Bangladesh from July 2014 to June 2015. A Total of 200 patients were selected by applying inclusion and exclusion criteria.