Transoral robotic surgery (TORS) has become an increasingly utilised treatment modality in the management of oropharyngeal squamous cell carcinoma (OPSCC). Postoperative haemorrhage, although uncommon, is a significant complication. To ameliorate this risk, transcervical ligation of branches of the external carotid artery (ECA) usually at the time of concomitant neck dissection, has been established and is advocated in the UK Head and Neck Cancer Guidelines. This systematic review and meta-analysis establish the evidence base to support this practice. Five studies totalling 2008 patients, undergoing TORS and mixed modality surgery were included. The overall rate of postoperative haemorrhage in patients undergoing TORS was 11.4% while risk of major haemorrhage was 4.4%. Arterial ligation was found to be protective against major haemorrhage across all transoral surgical modalities (OR 0.33, p 0.03) but it did not significantly affect overall haemorrhage rates. Predictably, concomitant anticoagulant therapy, T3-T4 tumours and history of prior irradiation were all associated with greater risk of developing postoperative haemorrhage. Major postoperative haemorrhage can be a catastrophic complication for the patient and surgeon. While this review has several limitations including the heterogeneity and retrospective, non-randomised nature of the included studies, the results do support its conclusion; prophylactic transcervical ligation of the ECA offers protection against major haemorrhage in patients undergoing TORS.