To explore the clinical features of programmed cell death-1 (PD-1) inhibitor-associated hypophysitis and improve the understanding of the disease. For the present retrospective case series study, the clinical data of patients with PD-1 inhibitor-associated hypophysitis who were treated at the Affiliated Hospital of Hebei University and the 3rd Hospital of Hebei Medical University from January 2020 to May 2023 were collected for analysis of clinical manifestations and prognosis. Fifteen cases of PD-1 inhibitor-induced hypophysitis were included, with 13 males and 2 females. The mean age of onset was (62.1±7.5) years, and the median time of onset was 6.5 (4.7, 11.6) cycles of PD-1 inhibitor. At diagnosis, 14 patients complained of gastrointestinal symptoms, and 12 patients complained of fatigue. There were 12, 1, 1, 5, and 1 cases of hyponatremia, hypokalemia, hypoglycemia, hypotension, and fever, respectively. Secondary adrenocortical insufficiency occurred in all cases. Moreover, four patients had secondary h