Study objectiveSudden cardiac death is the most common cause of non-traumatic death in collegiate athletes. Marfan syndrome poses a risk for sudden cardiac death secondary to aortic root dilation leading to aortic dissection or rupture. Arm span to height ratio (ASHR) > 1.05 has been proposed as a screening tool for Marfan syndrome in pre-participation examinations (PPE) for collegiate athletes but limited data exists on the association between ASHR and aortic root diameter (ARD). This study examines the relationship between ASHR and ARD and assesses for predictors of ARD. DesignRetrospective chart review. SettingNational Collegiate Athletic Association Division I University. Participants793 athletes across thirteen sports between 2012 and 2022 evaluated with PPE and screening echocardiogram. InterventionsNot applicable. Main outcome measures(1) Relationships between ASHR, SBP, BSA, and ARD amongst all athletes as well as stratified by ASHR >1.05 or ≤1.05 using univariate analysis. (2) Predictors of ARD using multivariate analysis using linear regression. Results143 athletes (18 %) had ASHRs > 1.05. Athletes with ASHR > 1.05 had higher ARD (2.99 cm) than athletes with ASHR ≤ 1.05 (2.85 cm). Weak correlations were noted between ASHR, ARD, and SBP. Multivariate analysis showed that BSA, male sex, and participation in swimming were predictors of ARD. ASHR was not predictive of ARD in regression analysis. ConclusionsThese findings showed a tendency towards higher ARD in athletes with ASHR >1.05 but this observation was not statistically significant in multivariate analysis.