Abstract Background and Aims Thrombotic microangiopathy (TMA) pathogenesis in kidney transplantation is poorly understood. The aim of this study was to evaluate donor and recipients risk factors for posttransplant TMA. Method In this retrospective multicenter national study, we identified both the case and 3M protocol kidney graft biopsies in 5258 recipients with TMA (n=57, 1.1 %) in 1994-2019. To further evaluate the effect of donor kidney on TMA development, the outcomes of the pair kidney grafts from the identical donors (n=43, 6 living donor, 1 pair kidney discarded, 6 insufficient data) as control group was analyzed. Results TMA occurred in 57 patients at 8th (median) post-operative day. Interestingly, neither histological nor laboratory signs of TMA were present in controls but in one case where TMA was evident in both recipients and in donor zero-hour biopsy. TMA associated with acute antibody mediated rejection was found in 11 cases (19%). Basic demographics between TMA and control group were similar, however longer cold ischemia time (p < 0,05, Figure 1) and more frequent delayed graft function (p < 0,05) were observed in TMA group. Patients with TMA experienced lower death-censored 5-year graft survival (56 vs. 84 %) in comparison with control group (p < 0,05, HR 2,904 (95% CI 1,411; 6,127), Figure 2). Conclusion TMA significantly affects the long-term kidney graft survival. Longer cold ischemia time was identified as the only risk factor and thus recipients genetic background is highly suspected in its pathogenesis. Figure 1 (Cold ischemia time) Figure 2 (Death-censored graft survival)