Introduction - FNAC of thyroid is minimally invasive , cost effective , simple and outpatient procedure. FNAC along with USG and Serum T3, T4, and TSH is the effective way to evaluate Thyroid lesions . According to the guidelines put forth by American Thyroid association, Serum TSH should be a part of initial assesment of thyroid lesions. Methods - It was a prospective study. 135 cases of thyroid lesions had undergone for FNAC and blood sample was taken for serum estimation of T3, T4, and TSH. Results were categorised using Bethesda system of reporting thyroid cytopathology 2023 and correlated with Serum T3, T4 and TSH. Results - Majority of cases were of colloid goitre ( 60 % ) followed by lymphocytic thyroiditis ( 14.8 % ). Thyroid lesions on FNAC were also classified on the basis of TBSRTC -2023. Out of 135 cases, 107 cases were fron Category 2 (Benign) followed by Category 1(non diagnostic - 11) and category 6 (Malignant - 7). Thyroid function status of 135 cases were also done and compared with Cytological findings. Out of 135 cases, majority of cases were Euthyroid (68.8 %) followed by Hypothyroid (21.5%) and Hyperthyroid (9.7%). Maximum number of euthyroid cases were of colloid goitre followed by adenomatoid nodule. Majority of cases of lymphocytic thyroiditis were hypothyroid. None of the malignant cases were hyperthyroid. Conclusion- FNAC along with Thyroid function tests can be used for early and accurate diagnosis of thyroid lesions avoiding unnecessary surgical interventions. Thyroid nodules usually show euthyroid status but in order to rule out biochemical euthyroidism , free T3 and T4 should be assessed.