Several genetic and environmental factors contribute to the development of multinodular goitre. A transcervical surgical resection is recommended for larger goitres, though a minority of cases may require sternotomy or thoracotomy. We present a case of a posterior substernal goitre that was resected with combined transcervical and robotically assisted thoracic approaches. A woman in her 30s with an enlarging thyroid goitre elected to proceed with surgical resection. CT imaging demonstrated significant extension of the goitre into the posterior mediastinum and a staged approach was decided on. Both the initial transcervical thyroidectomy and the subsequent robotically assisted resection of the mediastinal portion were successful, without major complications. While most substernal goitres can be resected transcervically, certain rare anatomic features, such as extension into the posterior mediastinum, warrant consideration of a thoracic approach. Specifically, a robotic-assisted resection poses several advantages over traditional, more invasive approaches.