Post-transplant diabetes mellitus (PTDM) is a complex condition arising from various factors including immunosuppressive medications, insulin resistance, impaired insulin secretion, and inflammatory processes. Its impact on patient and graft survival is a significant concern in kidney transplant recipients. PTDM's impact on kidney transplant recipients, including patient and graft survival and cardiovascular mortality, is a significant concern, given conflicting findings in previous studies. This meta-analysis was imperative to not only incorporate emerging evidence but also to delve into cause-specific mortality considerations. We aimed to comprehensively evaluate the association between PTDM and clinical outcomes, including all-cause and cardiovascular mortality, sepsis-related mortality, malignancy-related mortality, and graft loss, in kidney transplant recipients. PubMed, Ovid/Medline, Web of Science, Scopus, and Cochrane Library databases were screened and studies evaluating the effect of PTDM on all-cause mortality, cardiovascular mortality, sepsis-related mortality, malignancy-related mortality, and overall graft loss in adult kidney transplant recipients were included. 53 studies, encompassing a total of 138,917 patients, to evaluate the association between PTDM and clinical outcomes were included. Our analysis revealed a significant increase in all-cause mortality (RR 1.70, 95% CI 1.53 to 1.89, P<0.001) and cardiovascular mortality (RR 1.86, 95% CI 1.36 to 2.54, P<0.001) among individuals with PTDM. Moreover, PTDM was associated with a higher risk of sepsis-related mortality (RR 1.96, 95% CI 1.51 to 2.54, P<0.001) but showed no significant association with malignancy-related mortality (RR 1.20, 95% CI 0.76 to 1.88). Additionally, PTDM was linked to an increased risk of overall graft failure (RR 1.33, 95% CI 1.16 to 1.54, P<0.001). These findings underscore the importance of comprehensive management strategies and the need for research targeting PTDM to improve outcomes in kidney transplant recipients.