The thyroid gland is an important endocrine gland in human body. The organogenesis of thyroid gland is often disturbed leading to variety of morphological variations. The position, size of isthmus, posterior relations may vary greatly. Hence a descriptive cross sectional cadaveric study was conducted in western maharashtra population in india. The study was conducted on total of 60 thyroid glands (male-34, female-26) collected during routine dissection from adult cadavers in the anatomy department, B.J.Govt medical college, Pune. Presence or absence of isthmus, its dimentions, and posterior relations with tracheal rings were noted. Absence of isthmus was noted in total 5 cadavers, incidence is 8.33% , 3 in male cadavers ( 8.82%) and 2 in female cadavers (7.69%). Average length, breadth, thickness of isthmus was 16.1 mm, 16.53 mm, 3.24mm respectively. In maximum 13 out of 60 cadavers (21.66%) isthmus was anterior to tracheal rings 1,2,3 , in 10 cases (16.66% ) - tracheal rings 1,2,3,4. About 8 cases (13.33%) anterior to 2nd, 3rd tracheal ring. A wide variation was seen in the position of isthmus, as high as cricoid cartilage to as low as 8th tracheal ring. The size of isthmus was also varying related to only 1st tracheal ring and related to 1st to 8th tracheal rings. From the study it is evident that detail knowledge of the thyroid isthmus anatomy and its variations is necessary for surgeons and physicians to avoid undue complications during tracheostomies and in evaluation of scintigraphy.