Permanent hypoparathyroidism is common after thyroidectomy. The present study evaluated the risk for morbidity in patients operated with total thyroidectomy with and without permanent hypoparathyroidism. Data was retrieved from the Scandinavian Quality Register for Thyroid, Parathyroid, and Adrenal Surgery and cross-linked with the Swedish National Prescription Registry for Pharmaceuticals, the National Data Inpatient Registry, and Causes of Death Registry. Patients with benign thyroid disease were included. Permanent hypoparathyroidism was defined as treatment with active vitamin D for more than 6 months after thyroidectomy. Analyzed morbidity was evaluated by multivariable Cox's regression analysis and presented as hazard ratio and 95% confidence interval. There were 4,828 patients. The mean (standard deviation) follow-up was 4.5 (2.4) years. Some 239 (5.0 %) patients were medicated for permanent hypoparathyroidism. Patients with permanent hypoparathyroidism had an increased risk for renal insufficiency, hazard ratio 4.88 (2.00-11.95), and an increased risk for any malignancy, hazard ratio 2.15 (1.08-4.27). Patients with permanent hypoparathyroidism and known cardiovascular disease at the time of thyroidectomy had an increased risk for cardiovascular events during follow-up, hazard ratio 1.88 (1.02-3.47). Patients with permanent hypoparathyroidism after total thyroidectomy have an increased risk of long-term morbidity. These results are a cause of great concern.