Allogeneic hematologic cell transplantation (alloHCT) is the only curative therapy for many adults with hematological malignancies. However, it can be associated with substantial risks of morbidity and mortality that are dependent on patient comorbidity– or disease risk–related factors. Several pretransplantation prognostic scoring systems have been developed to estimate survival of patients undergoing alloHCT; however, there is significant interstudy variability in the predictive capacity of these assessment tools. We tested the prognostic capability of a composite scoring system including the disease risk index and HCT comorbidity index (DRCI). The DRCI scoring system was applied pretransplantation to determine whether it predicted clinical outcomes of 959 adult patients with hematological malignancies undergoing alloHCT from 2000 to 2013 at the University of Minnesota. The DRCI score categorized patients into 6 risk groups, with 2-year overall survival ranging between 74% for the very low-risk DRCI group and 34% for the very high-risk DRCI group. In multiple regression analyses adjusted for patient age and donor type, the risk of overall mortality independently increased as the DRCI score increased. Additionally, the DRCI score independently predicted risk of relapse, disease-free survival, and graft-versus-host disease–free/relapse–free survival. Our data demonstrate that the pretransplantation DRCI scoring system predicts outcomes after alloHCT and can be used to guide clinical decision making for patients considering alloHCT.