Background: The use of immunotherapy to treat recurrent/metastatic squamous cell carcinoma of the head and neck has become a popular research topic in recent years, and many clinical trials have been carried out. Objectives: To systematically evaluate the efficacy and safety of PD-1/PD-L1 inhibitors in the treatment of recurrent/metastatic head and neck squamous cell carcinoma. Methods: We searched PubMed, Embase, Cochrane Library and other databases up to 1 November 2019 for publications reporting the use of PD-1/PD-L1 inhibitors in the treatment of squamous cell carcinoma of the head and neck. Revman 5.0 was used for combination analysis, and the overall survival (OS), progression-free survival (PFS), overall response rate (ORR), and adverse events were determined. Results: Five articles were included. Compared with other treatment methods, this meta-analysis showed that treatment with PD-1/PD-L1 inhibitors can significantly improve OS (P < 0.0001), but there was no significant improvement in PFS or ORR. The risk of anaemia and nausea was significantly reduced by treatment with PD-1/PD-L1 inhibitors. Conclusions and Significance: Treatment with PD-1/PD-L1 inhibitors alone can improve the overall survival rate for recurrent/metastatic squamous cell carcinoma of the head and neck but there is no obvious advantage in other aspects and adverse events.