Objective:The mortality was seen in the early period after kidney transplantation is one of the most undesirable consequences of kidney transplant treatment. This study was aimed to evaluate the factors affecting the 1st-year mortality in patients who underwent living donor kidney transplantation (LDKT) in our center. Material and Method: Adult patients who underwent LDKT developed mortality within the 1st-year in our center between 2008 and 2020. Mortality group and the control group are compared according to donor and recipient characteristics. The risk factors that have an adjusted effect on 1st-year mortality after kidney transplantation were evaluated by cox regression survival analysis. Results: Total mortality incidence was 8.35% and the 1st-year mortality incidence was 1.67%. Median dialysis duration (13 months vs. 3 months) was longer in the mortality-group, p=0.022. Cardiovascular disease (CVD) was more common in the mortality-group (50% vs. 31.1%), p=0.037. Median HLA mismatch numbers was higher in the mortality-group (4 vs. 3), p=0.027. According to Model 1, in terms of 1st-year mortality, each 1 year increment in recipient's age increases the mortality by 1.034 times, and dialysis treatment increases the mortality 2.5 times. According to Model 2, in terms of 1st-year mortality, each 1 year increment in recipient's age increase the mortality by 1.039 times, dialysis treatment increases the mortality 2.8 times and each 1 mismatch increase in human leukocyte antigen (HLA) mismatch numbers increases the mortality by 1.3 times. Receiver operating characteristic analysis showed that the moderate predictive power for recipient age was area under the curve (AUC) 0.734 (95% CI 0.623-0.844, p<0.001) and the weak level predictive power AUC was for HLA mismatch 0.639 (95% CI 0.519-0.759, p=0.030) in terms of 1st-year mortality. Conclussion: This study presented that the 1st-year mortality results of our organ transplant center are similar to the national and international literature. We determined recipient age, dialysis treatment and HLA mismatch numbers as independent risk factors affecting 1st-year mortality after LDKT.