Introduction: Fine needle aspiration cytology is a very helpful and relatively noninvasive techniques in the diagnosis of various thyroid lesions. The main aim of thyroid FNAC is to distinguish benign from malignant lesion and to determine the cases that require surgery.

Methods: A one-year retrospective study was done from August 2024 to July 2023 in all patients (both males and females) who presented with thyroid swelling in Department of Endocrinology BSMMU. Detailed medical history along with thorough physical examination and relevant biochemical and radiological investigations were taken into consideration. FNA cytology was done, smear were made and stained using Leishman/Giemsa and Haematoxylin/Eosin stain and they were examined under microscope for cytological diagnosis.

Results: Among 226 cases, 200 were females and 26 were males. 202 were benign lesion whereas 25 were cases of malignancy. The most common age group that presented with thyroid lesion was 21-30 years. The incidence of malignancy seemed to increase with age. Among the benign conditions, the most common was colloid goiter, I.e 120 cases and among the malignancies follicular neoplasm, ie.17 cases.

Conclusions: Thyroid disorders are one of the very common health problems that we come across. Benign lesion are far more common. Due to introduction of this technique, the incidence of surgery in thyroid has been reduced considerably. The endocrine surgeon have widely accepted FNAC of thyroid.