Background: Anthracycline chemotherapy is commonly used in the treatment of diffuse large B-cell lymphoma (DLBCL) patients. Treatment-related cardiotoxicity (TRC) may be observed during treatment and may induce severe cardiac failure or cardiac arrhythmia as the main cause of death, even several years after chemotherapy implementation. Herein, we performed a study to investigate the prognostic value of gated myocardial perfusion imaging (G-MPI) summed rest score (SRS) for the early detection of TRC caused by anthracycline chemotherapy in DLBCL patients.Methods: A total of 36 DLBCL patients were enrolled, and a series of parameters from the same individual patient were compared between baseline and after the end of the 6th R-CHOP chemotherapeutic regimen. According to whether TRC occurred during the observation period, the patients were divided into two groups, and parameters related to cardiac function were compared.Results: SRS in G-MPI and QTc interval in electrocardiogram were significantly different before and after chemotherapy (P = 0.012 and P = 0.015, respectively).By comparing parameters related to cardiac function between the TRC group (n = 22) and the no-TRC group (n = 14), only SRS was significantly different (P = 0.012). Multivariate logistic regression analysis showed that the SRS level was the only independent predicator for TRC (P = 0.018, HR = 6.053, 95% CI: 1.364-26.869). Receiver operating characteristic curve analysis identified an optimal SRS cutoff of >1for predicting TRC after anthracycline chemotherapy (P< 0.001).Conclusion: The G-MPI SRS level was an early indicator for TRC surveillance in DLBCL patients after anthracycline chemotherapy, thus contributing to early treatment and a subsequent decrease in mortality caused by such cardiovascular complications.