Objective: To compare age related histomorphological changes through cytology (Bethesda category) and histopathology in thyroid nodules. Study design and setting: This cross sectional study was conducted at the Department of Anatomy, BMSI, JPMC Karachi from 31-March-2021 to 31-August-2021. Methodology: Total n=120 patients of all ages, genders and ethnicities that underwent surgery for thyroid nodules were included after taking duly signed consent. On the basis of cytological reports (FNAC) patients were grouped according to age and gender. Processed paraffin blocks were sectioned at a thickness of 5µm and then were stained with Haematoxylin and Eosin (H&E) for histological evaluation. Masson trichrome stain was used to observe fibrosis, that was measured through Image J Fiji software. Results: We evaluated that out of 120 patients, male to female ratio was 1:5.67. Among various ethnic groups; Urdu speaking (40.8%) with mean age of 40.3% were commonly affected. Histopathological examination revealed that most common benign lesion was colloid nodular hyperplasia and papillary carcinoma was the most common malignant lesion. Highest percentage of fibrosis (36%) was seen in middle aged participants (p-0.045). Basement membrane thickness with lowest percentage (12%) was observed in younger age participants while highest (31%) was measured in older aged participants (p-0.001). Accuracy score of FNAC showed sensitivity 59%, specificity 96.6%, accuracy 86%, positive predictive value (PPV) 86% and negative predictive value (NPV) 87%. Conclusion: With progression in age thyroid gland undergo histomorphological changes, early diagnosis will help in categorical nomenclature and its implications for subsequent management of patients with thyroid lesions