Objective Total thyroidectomy is associated with a high risk of postoperative hypoparathyroidism, mainly due to the unintended surgical damage to the parathyroid glands or their blood supply. It is possible that surgeons who also perform parathyroid surgery see lower rates of postoperative hypoparathyroidism. In a single institution, we investigated the effects of restricting total thyroidectomy operations for Graves’ disease to two surgeons who performed both thyroid and parathyroid surgeries. We aimed to evaluate the rates of postoperative hypoparathyroidism in a 10-year period with primary attention toward patients with Graves’ disease. Design Retrospective cohort study from a single institution. Methods We defined the rate of permanent hypoparathyroidism after total thyroidectomy as the need for active vitamin D 6 months postoperatively. Between 2012 and 2016, seven surgeons performed all thyroidectomies. From January 2017, only surgeons also performing parathyroid surgery carried out thyroidectomies for Graves’ disease. Results We performed total thyroidectomy in 543 patients. The rate of permanent hypoparathyroidism decreased from 28% in 2012–2014 to 6% in 2020–2021. For patients with Graves’ disease, the rate of permanent hypoparathyroidism decreased from 36% (13 out of 36) in 2015–2016 to 2% (1 out of 56) in 2020–2021. In cancer patients, the rate of permanent hypoparathyroidism decreased from 30% (14 out of 46) in 2012–2014 to 10% (10 out of 51) in 2020–2021. Conclusion Restricting thyroidectomy to surgeons who also performed parathyroid operations reduced postoperative hypoparathyroidism markedly. Accordingly, we recommend centralisation of the most difficult thyroid operations to centres and surgeons with extensive experience in parathyroid surgery. Significance statement Thyroid surgery is performed by many different surgeons with marked differences in outcome. Indeed, the risk of postoperative permanent hypoparathyroidism may be very high in low-volume centres. This serious condition affects the quality of life and increases long-term morbidity and the patients develop a life-long dependency of medical treatments. We encountered a high risk of hypoparathyroidism after the operation for Graves’ disease and restricted the number of surgeons to two for these operations. Further, these surgeons were experienced in both thyroid and parathyroid surgeries. We show a dramatic reduction in postoperative hypoparathyroidism after this change. Accordingly, we recommend centralisation of total thyroidectomy to surgeons with experience in both thyroid and parathyroid procedures.