Hearts from older donors are increasingly utilized for transplantation due to unmet demand. Conflicting evidence exists regarding the prognosis of recipients of advanced age donor hearts, especially in young recipients. A retrospective analysis was performed on 11 433 patients aged 18 to 45 who received a cardiac transplant from 2000 to 2017. Overall, 10 279 patients received hearts from donors less than 45 and 1145 from donors greater than 45. Recipients of older donors were older (37 vs. 34 years, P < .01) and had higher rates of inotropic dependence (48% vs. 42%, P < .01). However, groups were similar in terms of comorbidities and dependence on mechanical circulatory support. Median survival for recipients of older donors was reduced by 2.6 years (12.6 vs. 15.2, P < .01). Multivariable analysis demonstrated donor age greater than 45 to be a predictor of mortality (HR 1.18 [1.05-1.33], P = .01). However, when restricting the analysis to patients who received a donor with a negative preprocurement angiogram, donor age only had a borderline association with mortality (HR 1.20 [0.98-1.46], P = .06). Older donor hearts in young recipients are associated with decreased long-term survival, however this risk is reduced in donors without atherosclerosis. The long-term hazard of this practice should be carefully weighed against the risk of waitlist mortality.