Background: Thyroid malignancies present significant diagnostic and therapeutic challenges. With increasing global incidence, specific demographic data is vital to optimize management protocols. This study aims to correlate the clinical diagnosis, cytological opinions and histological confirmational diagnosis after surgical interventions in a tertiary care hospital. Material and Methods: This retrospective study was conducted over a six years period from 2018 to 2024. 102 patients with histologically confirmed differentiated thyroid lesions were included. Data on demographics, clinical diagnosis, cyto-histological diagnosis were analysed. Results: Among thyroid lesions, the majority of the lesions were colloid goitre (28.4%) and colloid nodular goitre (15.6%) followed by adenomatous goitre (11.7%), papillary carcinomna thyroid (11.7%), multinodular goitre (8.8%), follicular carcinoma (7.8%), hurthle cell neoplasm (6.8%), follicular variant of papillary carcinoma (2.9%), hashimoto thyroiditis (1.96%), medullary carcinoma (0.98%), autoimmune thyroiditis (0.98%), follicular adenoma (0.98%), and toxic nodular goitre (0.98%). Clinical evaluation of thyroid lesion and their histopathological diagnosis showed overall Sn-sensitivity of 94.4%, Sp-specificity of 83.3%, Positive Predictive Value - PPV – 93.1%, Negative Predictive value - NPV-86.2%. Cytological and their histopathological diagnosis showed overall Sn-sensitivity of 98.5%, Sp-specificity of 53.3%, Positive Predictive Value - PPV – 82.7%, Negative Predictive value - NPV-94.1%. Conclusion: The purpose of this study was to compare the results of FNAC using Bethesda system with the final histological diagnosis and the initial clinical diagnosis in order to determine the accuracy of the diagnosis of thyroid lesions. The study findings reinforce the significance of comprehensive preoperative evaluation, definite treatment and long-term follow-up in differentiated thyroid cancers