During recent years, more radical surgery for thyroid disease, i.e., total instead of subtotal resection, has been evident. Results following this strategy on national levels are scarce. From 2004 to 2006, 26 Scandinavian Departments registered 3,660 thyroid operations in a database. Risk factors for complications were analyzed with multiple logistic regression. After thyroidectomy, re-bleeding occurred in 2.1% and was associated with older age (OR 1.04; p < 0.0001) and male gender (OR 1.90; p = 0.014). Postoperative infection occurred in 1.6% and associated with lymph node operation (OR 8.18; p < 0.0001). Postoperative unilateral paresis of the recurrent laryngeal nerve was diagnosed 3.9% and bilateral paresis in 0.2%. Unilateral paresis was associated with older age, intrathoracic goiter, thyreotoxicosis, and if routine laryngoscopy was practiced (OR 1.92; p = 0.0002). After 6 months, the incidence of nerve paresis was 0.97%. After bilateral thyroid surgery (n = 1,648), hypocalcaemia treated with vitamin D analogue occurred in 9.9% of the patients at the first follow-up and in 4.4% after 6 months. Complications to thyroid surgery are not uncommon. The high frequency of hypocalcaemia treated with vitamin D after 6 months is a cause of concern.