Introduction Fine needle aspiration cytology (FNAC) forms part of the routine workup for suspicious thyroid nodule. Whilst cytological analysis is less precise than histological assessment, it is quick and easy to perform and may avoid the need for invasive and potentially risky surgery. Methods This retrospective study spanning a 10-year period compared pre-operative FNAC with post-operative histology results to establish the accuracy of diagnosis and malignancy rates within our population. These results were then compared to the published figures in the literature. Results The histological reports of 659 consecutive cases of thyroid surgery between 2006 and 2015 were retrieved from our hospital’s database. Among the 471 patients (71.5%) who underwent preoperative FNAC, the postoperative histology was reported as benign in 352 (74.7%) and malignant in 119 cases (25.3%). PTC was the commonest histological diagnosis. Thy1 grade was reported in 165 (30%) cases, with 19.4% had a final histological diagnosis of malignancy. 85.3% of patients in the Thy2 group had a benign final histological diagnosis, while 14.7% had malignancy (false negative results). Malignancy was found in 89% of Thy4 and 100% of Thy5 group patients. Conclusions Rates of malignancy varied considerably from those in the published literature. Each centre should be able to quote a local malignancy rate during patient counselling. It is also prudent for all units performing thyroid diagnostics to investigate the factors that might lead to inaccuracies in reporting.