OBJECTIVE: To evaluate the rate of complications and the risk factors in relation to the extent of surgery in patients undergoing thyroidectomy in a tertiary university center.DESIGN: Data were collected retrospectively from 2,043 consecutive patients who underwent thyroid surgery for various thyroid diseases at the University Hospital of Patras, Greece, between January 1996 and December 2007. Recurrent laryngeal nerve palsy (RLNP) and hypoparathyroidism were set as the primary end points, while hematoma and wound infection were set as the secondary endpoints.RESULTS: Total, near-total and subtotal thyroidectomy was performed in 1,149,777 and 117 patients, respectively. Transient RLNP occurred in 34 (1.6%) and permanent in 19 (0.9%) patients. Multivariate logistic regression analysis showed that extended resection (OR-odds ratio-1.6), Graves' disease (OR 2.7), thyroiditis (OR 2.1), recurrent goiter (OR 2.3) and thyroid malignancy (OR 1.7) were all independent risk factors for transient RLNP, whereas Graves' disease (OR 2.2) and recurrent goiter (OR 1.7) emerged as independent risk factors for permanent RLNP. The rates of transient and permanent hypoparathyroidism were 27.8% and 4.8%, respectively. Multivariate analysis for transient hypoparathyroidism revealed that the extent of surgical resection (OR 2.2), Graves' disease (OR 2.1), recurrent goiter (OR 1.7), female gender (OR 1.5) and specimen weight (OR 1.6) were independent predictors. However, the extent of surgical resection (OR 2.7), Graves' disease (OR 1.8), recurrent goiter (OR 1.5) and malignant disease (OR 1.5) were independent risk factors for permanent hypoparathyroidism. Postoperative wound infection and hematoma occurred in 6 (0.3%) and 27 (1.3%) patients, respectively. No correlation was observed between wound infection or postoperative hemorrhage and the extent of surgery.CONCLUSIONS: Despite the higher morbidity, total thyroidectomy is emerging as an attractive surgical option even for benign thyroid disease due to the risk of subclinical (occult) malignancy, the possibility of goiter relapse as well as of the increased risk of complications following reoperation.