Objective:To investigate the relationship between 18F-FDG PET/CT Lugano lymphoma response evaluation criteria and prognosis of patients with diffuse large B-cell lymphoma (DLBCL) at the end of chemotherapy. Methods:A total of 131 patients with DLBCL (63 males, 68 females, age (50.3±17.0) years) who underwent 18F-FDG PET/CT at the end of chemotherapy in the Fourth Hospital of Hebei Medical University from July 2013 to January 2021 were analyzed retrospectively. 18F-FDG PET/CT Lugano lymphoma response evaluation criteria was used to evaluate the response (complete remission (CR), partial remission (PR), stable disease (SD) and progressive disease (PD)). Progression-free survival (PFS) and overall survival (OS) were followed up. Kaplan-Meier survival analysis was used for univariate analysis of clinical parameters and imaging parameters, and Cox proportional hazards regression model was used for multivariate analysis to explore related factors affecting the prognosis of patients with DLBCL. Results:The median follow-up time was 35.47 months for 131 patients with DLBCL. The 5-year PFS rate was 57.3%(75/131), and the 5-year OS rate was 84.0%(110/131). There were 74 cases of CR, 37 cases of PR and 20 cases of PD. Univariate analysis showed that the Lugano lymphoma response evaluation criteria was the influencing factor of PFS and OS (PFS, χ2=72.25, P<0.001; OS, χ2=11.97, P=0.003). Deauville score (DS) of patients with DLBCL was also the influencing factor for PFS ( χ2=62.46, P<0.001) and OS ( χ2=19.95, P<0.001). Ann Arbor stage, Eastern Cooperative Oncology Group physical state (ECOG PS) score and international prognostic index (IPI) were the influencing factors for PFS ( χ2 values: 10.31-15.80, all P<0.05). Ann Arbor stage, ECOG PS score, number of extranodal organ involved, β 2 microglobulin, and IPI were the influencing factors for OS ( χ2 values: 4.97-30.57, all P<0.05). Cox multivariate analysis showed that Lugano lymphoma response evaluation criteria, Ann Arbor stage and ECOG PS score were independent prognostic factors for PFS (relative risk ( RR) and 95% CI: 8.841(4.764-16.405), 1.434(1.111-1.852), 2.125(1.205-3.746), P values: <0.001, 0.006, 0.009) and OS ( RR(95% CI): 3.276(1.304-8.235), 9.728(2.216-42.669), 2.506(1.040-6.039), P values: 0.012, 0.003, 0.041). Conclusion:18F-FDG PET/CT Lugano lymphoma response evaluation criteria can precisely evaluate the prognosis of patients with DLBCL at the end of chemotherapy.