Hematopoietic stem cell transplantation (HSCT) is a highly successful treatment option for many hematological malignancies. Several adverse effects can be seen in HSCT due to the infusion and damage caused by the conditioning regimens. Cardiovascular adverse effects are relatively common during HSCT, and they have the potential to cause devastating complications. The aim of present study was to evaluate the transplantation-related cardiac adverse effects and determine the risk factors in patients undergoing HSCT at our institution. A retrospective analysis has been performed in 662 patients who was treated at Hacettepe University Stem Cell Transplantation Unit. Amongst the 622 patients, 318 (51.1 %) underwent autologous and 304 (48.9 %) underwent allogeneic HSCT. The frequency of the cardiac adverse effects was found to be 10.8 % in all the study population. The most common adverse effect was tachyarrhythmia, constituting 7.9 % of all population. These adverse effects were mostly occurred in lymphoma patients (14 %). Nineteen (3.0 %) of all patients developed atrial fibrillation mostly on the 4th day (range of 1-9 days) after transplantation. Life-threatening events are extremely rare. These adverse effects appear to be related to the type of transplantation rather than the underlying disease. Therefore, close follow-up of patients is important during the peri-transplantation period.