Survivors of allogeneic stem cell transplant (SCT) receive intensive cancer treatments that are associated with cardiovascular dysfunction. Markers of vascular age can indicate early signs of adverse (cardio)vascular changes; however, the impact of SCT on these makers is unknown. We aimed to determine the short (3 months) and longer-term (≥2 years) effect of SCT on markers of vascular age in hematologic cancer survivors compared with an age-matched noncancer control group.The short-term effects of SCT, markers of vascular age (aortic compliance, arterial elastance, and ventricular-vascular coupling) were assessed via cardiac magnetic resonance imaging (cardiac and aortic volumes) before and ≈3 months post-SCT in 13 short-term survivors and compared with 11 controls. The longer-term impact was assessed by comparing 14 long-term survivors (6.5 [2-20] years post-SCT) to the short-term survivors (post-SCT) and controls (n=16).The groups were similar for age and body mass index. In the short-term survivors, no significant group-by-time interactions were observed for any markers of vascular aging from pretransplant to posttransplant (net difference for change in compliance between groups -0.07 [95% CI, -1.49 to 1.35]). For the time-course analysis, aortic compliance was significantly lower in both SCT groups (overall =0.007) compared with controls, whereas ventricular-vascular coupling was higher in both survivor groups as was arterial elastance in long-term SCT survivors (ie, worse; <0.01 for all).PThis study provides evidence of an accelerated vascular aging phenotype in allogeneic SCT survivors and provides insight into the increased burden of cardiovascular disease among hematologic cancer survivors.