Post irradiation xerostomia is a common side effect of irradiation to the head and neck region, with up to 90% of patients reporting some symptoms. Submandibular glands account for 70% of resting saliva production. Surgically transferring the submandibular gland to the submental region and shielding it during radiotherapy has been postulated to reduce post irradiation xerostomia. The authors of this systematic review summarise the evidence in this field. Seven studies with 369 participants were identified. There were two RCTs, two prospective cohort studies, two case series and one controlled clinical trial. Submandibular gland transfer +/- shielding was compared to no intervention. One study compared submandibular gland transfer + shielding to standard radiotherapy + pilocarpine. The authors conclude that salivary gland transfer is an effective method for preventing post irradiation xerostomia based on both objective (stimulated salivary flow) and subjective measures, and furthermore is more effective than pilocarpine. There is no difference in survival outcomes. Although the results are impressive, submandibular gland transfer should be taken in the context of an already intensive treatment schedule for head and neck cancer patients, and does involve an additional surgical procedure. It is not recommended if there is suspicion of regional lymph node involvement in level 1b. The authors do not comment on whether patients received IMRT or small field radiotherapy, which would cause less radiation-induced fibrosis in the salivary glands.