OBJECTIVE To assess the efficacy of fine needle aspiration cytology in the evaluation of thyroid lesions. METHODS The retrospective study comprised data of all patients who presented for fine needle aspiration cytology at the Shifa International Hospital, Islamabad, between January 2009 and April 2011. The data was retrieved from the departmental records and the results were recorded. All cases who underwent subsequent surgery were also retrieved and histopathology results were compared with the cytology results. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were calculated. RESULTS Of the 327 patients, the results were inconclusive in 18 (5.5%), benign in 230 (70.3%), suspicious in 64 (19.6%) and malignant in 15 (4.6%) cases. Besides, 59 (18%) of these patients underwent subsequent surgery. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of fine needle aspiration cytology was calculated to be 85.7%, 73.3%, 50%, 94.2% and 76.2% respectively. CONCLUSIONS Fine needle aspiration cytology is a reasonably sensitive, specific and accurate initial diagnostic test for pre-operative evaluation of patients with thyroid swellings. The clinicians should be encouraged to use the procedure as it is minimally invasive and easily performed in an outpatient setting.