Allogeneic hematopoietic cell transplantation is increasingly utilized in older adults. This study prospectively evaluated the prognostic utility of geriatric assessment domains prior to allogeneic transplantation in recipients aged 50 years and over. Geriatric assessment was performed prior to transplant, and included validated measures across domains of function and disability, comorbidity, frailty, mental health, nutritional status, and systemic inflammation. A total of 203 patients completed geriatric assessment and underwent transplant. Median age was 58 years (range 50-73). After adjusting for established prognostic factors, limitations in instrumental activities of daily living (HR 2.38, 95%CI: 1.59-3.56; P<0.001), slow walk speed (HR 1.80, 95%CI: 1.14-2.83; P=0.01), high comorbidity by hematopoietic cell transplantation-specific comorbidity index (HR 1.56, 95%CI: 1.07-2.28; P=0.02), low mental health by short-form-36 mental component summary (HR 1.67, 95%CI: 1.13-2.48; P=0.01), and elevated serum C-reactive protein (HR 2.51, 95%CI: 1.54-4.09; P<0.001) were significantly associated with inferior overall survival. These associations were more pronounced in the cohort 60 years and over. Geriatric assessment measures confer independent prognostic utility in older allogeneic transplant recipients. Implementation of geriatric assessment prior to allogeneic transplantation may aid appropriate selection of older adults.