We conducted this meta-analysis to investigate the overall incidence and risk of endocrine complications in cancer patients treated with PD-1 inhibitors. Methods: Pubmed, Embase and oncology conference proceedings were searched for relevant studies. Results: In comparison with chemotherapy or everolimus or cetuximab control, PD-1 inhibitors significantly increased the risk of all grade hypothyroidism (relative risk: 6.38; 95% CI: 3.78-10.77; p < 0.001) and hyperthyroidism (relative risk: 5.08; 95% CI: 2.55-10.14; p < 0.001), but not for hypophysitis. When compared with ipilimumab control, the risk of all grade hyperthyroidism and hypothyroidism with PD-1 inhibitors monotherapy seemed to be higher than ipilimumab, while the risk of hypophysitis was lower than ipilimumab. Conclusion: Treatment with PD-1 inhibitors is associated with an increased risk of developing hypothyroidism and hyperthyroidism, but not for hypophysitis.