Abstract : Thyroid is an endocrine gland which can be afflicted by various diseases of endocrine, inflammatory or neoplastic origin. The incidence of thyroid malignancy has increased in the recent years and most commonly encountered in younger age groups. The new classification introduced a borderline category of thyroid tumors which significantly impacted pathology practice. This descriptive study was done in at Dr. D. Y. Patil Medical College and Hospital. A total of 50 cases of thyroid tumors were included for this study. Patients were diagnosed according to classification proposed by WHO in 2004 and the slides were reevaluated and the new WHO classification 2017 diagnosis was also applied also old classification was compared with new classification. Among the 50 thyroidectomy specimens, maximum number of cases (34%) were seen in the age group of 31-40 years and only 16% of the cases in 41-50 age group. Comprising 80% of cases, females were higher in number than males. The ratio of female to male being 4:1. On recateogrisation according to new(latest) WHO 2017 classification, tumors were classified into 3 groups as benign, borderline, malignant. In our study malignant tumor constituted 50% of the cases, followed by borderline comprising 26% of the cases followed by benign comprising 24% cases. Diagnosis of borderline group of thyroid tumor should emphasized as Pathologists are no longer forced to decide between benign and malignant—it can be a borderline or precursor tumor and also this group can be closely followed by the surgeons.