Abstract： Objective:To investigate the efficacy of programmed cell death-1 (PD-1) inhibitor combined with immunochemotherapy in the treatment of refractory primary mediastinal large B-cell lymphoma (PMBCL).Methods:The clinical data of 2 refractory PMBCL patients who were achieving remission after applying PD-1 inhibitor combined with immunochemotherapy in Qilu Hospital of Shandong University (Qingdao) in July 2019 and January 2020 were retrospectively analyzed, and the relevant literature was reviewed.Results:The two patients were initially treated with CDOPE and R-CDOPE regimens, respectively, but the disease did not reach remission state. Later, they were adjusted to PD-1 inhibitor combined with immunochemotherapy to achieve remission. Radiotherapy and autologous hematopoietic stem cell transplantation were used as consolidation treatment, and maintenance therapy with PD-1 inhibitors was effective and had a good safety profile.Conclusions:For refractory PMBCL patients, PD-1 inhibitor combined with immunochemotherapy may have good efficacy.