BackgroundABO-incompatible living-donor kidney transplantation (LDKT) requires immunotherapy and plasma exchange therapy (PEX). PEX with albumin replacement fluid reportedly decreases fibrinogen levels. However, no reports have described the effects of PEX with albumin replacement fluid on blood coagulation parameters and blood loss during the perioperative period. Therefore, we investigated the effects of preoperative PEX on blood coagulation parameters and blood loss during the perioperative period in patients undergoing ABO-incompatible LDKT as measured by rotational thromboelastometry (ROTEM®).MethodsTwenty-eight patients undergoing LDKT were divided into the PEX group (ABO incompatible with PEX, n = 13) and non-PEX group (ABO compatible without PEX, n = 15). ROTEM® parameters, standard laboratory test parameters, bleeding volume, and transfusion volume were compared between PEX and non-PEX group. MCEplatelet, which represents platelet contribution to clot strength and where “MCE” stands for maximum clot elasticity, was calculated from the difference in MCE between EXTEM and FIBTEM.ResultsThe bleeding volume during surgery and the intensive care unit (ICU) stay was significantly higher in the PEX than non-PEX group (p < 0.01). Maximum clot firmness (MCF) of EXTEM (MCFEXTEM), MCFFIBTEM, and MCEplatelet was significantly lower in the PEX than non-PEX group (p < 0.01). In the PEX group, the bleeding volume during surgery was very strongly correlated with the baseline MCFEXTEM and MCEplatelet, and the bleeding volume during the ICU stay was strongly correlated with the postoperative MCFEXTEM and MCEplatelet.ConclusionsThese results suggest that the increased blood loss in the PEX group during surgery and the ICU stay was associated with decreased platelet contribution to clot strength as measured by ROTEM®.Trial registrationUMIN-Clinical Trial Registry UMIN000018355. Registered 21 July 2015.Electronic supplementary materialThe online version of this article (10.1186/s12871-018-0536-2) contains supplementary material, which is available to authorized users.