Allogeneic stem cell transplantation (alloSCT) remains the established main treatment option with curative potential for many hematologic malignancies. We conducted a retrospective analysis of 104 adult patients who underwent allogeneic stem cell transplantation between March 2013 and November 2023. Kaplan‒Meier survival analysis, the chi-square test, and Cox regression models were used to identify risk factors and outcomes. The median follow-up of the cohort was 19 (0.3-128.1) months. The median age of the recipients was 49 (19-65) years, and 57 (54.8%) recipients were males. Ninety (86.5%) patients had a matched sibling, and 14 (13.5%) had a haploidentical donor. According to the multivariable analysis, a body mass index (BMI) ≥ 30 kg/m2 (p = 0.02) and status without chronic graft-versus-host disease (cGVHD) (p = 0.04) were significantly associated with worse overall survival. A BMI ≥ 30 kg/m2 was also predictive of worse relapse-free survival (p = 0.01). The cumulative incidence rates of nonrelapse mortality (NRM) and relapse mortality (RM) at 1 year were 8.5% (95% CI
4.3-16.5%) and 26.7% (95% CI
19.1-37.4%), respectively. Patients without cGVHD had significantly higher RM than patients with cGVHD (p <
0.002), whereas patients with cGVHD had significantly higher NRM (p = 0.01). Patients with a BMI ≥ 30 kg/m2 had significantly more posttransplant fatal events (p <
0.002). Our analysis revealed that a BMI ≥ 30 kg/m2 and a status without cGVHD were significantly associated with worse OS. NRM was higher in patients with cGVHD, whereas patients without cGVHD died mostly from relapses.