The correct surgical approach to mediastinal goitre is not always well defined. We reviewed why and when our patients required a transthoracic approach. From 1979 to 1998, on 7.480 patients who underwent thyroid surgery in our hospital, 374 (5%) had a goitre whose greater bulk was inferior to the thoracic inlet; 43 patients of these last ones (11%) required a transthoracic approach. General anaesthesia was performed in all patients and orotracheal intubation was selective in 11 cases (double lumen tube of Carlens). In 34 cases, the first approach was a cervicotomy, followed by sternotomy in 23 cases or right posterolateral thoracotomy in 11 cases. Three patients underwent a sternotomy and 6 a thoracotomy only. We had neither perioperative mortality nor major complications. The mean hospital stay was 5 days. Mean goitre weight was 430 g and on average the greater diameter was 13 centimetres. The removal of a substernal goitre can be difficult and risky via the cervicotomy only. A transthoracic approach is often required in the case of greater secondary, primary and recurrent mediastinal goitres.