Total thyroidectomy for substernal goiter occasionally requires a sternotomy associated with a cervical incision. We sought to analyze the postoperative complications of thyroidectomy for substernal goiters in our center and more precisely the complications related to the sternotomy. All patients who underwent total thyroidectomy for substernal goiter in our center between 2007 and 2016 were reviewed retrospectively. Patients with combined cervical incision and sternotomy (ST group, n=16) were compared to those with cervical incision alone (CT group, n=54), with regard to postoperative complications. Risk factors for the occurrence of postoperative complications were investigated in this population. A total of 24 patients (34.2%) had one or more postoperative complications. The incidence of transient hypoparathyroidism and recurrent laryngeal nerve injury were higher in the ST group (P=0.001 and P=0.052, respectively). The median duration of hospitalization was longer in the ST group (P<0.001). Eighteen patients (25.8%) had a malignant tumor on final pathology. In univariate analysis, the following risk factors for transient postoperative hypoparathyroidism were identified: sternotomy, preoperative symptomatic character and thyroid height (P=0.001, P=0.009 and P=0.013, respectively). In multivariable analysis, only sternotomy was an independent risk factor for postoperative transient hypoparathyroidism (OR=4.48 [1.1; 18], P=0.035). Sternotomy is associated with added morbidity that is not negligible. This surgical approach should be reserved for substernal goiters that descend into the posterior mediastinum, below the level of the aortic arch, when there is suspicion of carcinoma with loco-regional invasion, or when the thyroid tissue is located mainly intrathoracically (conical shaped thyroid, asymptomatic goiter, ectopic thyroid).