Background: Aging has been associated with increasing common bile duct (CBD) diameter and reported as independently predictive of the likelihood of choledocolithiasis. These associations are controversial with uncertain diagnostic utility in patients presenting with symptomatic disease. The current study examined the relationship between age, CBD size, and the diagnostic probability of choledocolithiasis. Methods: Symptomatic patients undergoing evaluation for suspected choledocolithiasis from January 2008 to February 2011 were reviewed. In the cohort without choledocolithiasis, the relationship between aging and CBD size was examined as a continuous variable and by comparing mean CBD size across stratified age groups. Multivariate analysis examined the relationship between increasing age and diagnostic probability of choledocolithiasis in all patients. Results: Choledocolithasis was diagnosed by MR cholangiopancreatography (MRCP) or endoscopic retrograde (ERCP) in 496 of 1,000 patients reviewed. Mean CBD was 6.0 mm (±2.8 mm) in the 504 of 1,000 patients without choledocolithiasis on ERCP/MRCP. Increasing age had no correlation with CBD size as a continuous variable (r2 = 0.011, p = 0.811). No difference occurred across age groups (Kruskal-Wallis, p = 0.157). Age had no association with diagnostic likelihood of choledocolithiasis (AOR [95% CI] 0.99 [0.98-1.01], adjusted-p = 0.335). Conclusion: In a large population undergoing investigation for biliary disease, increasing age was neither associated with increasing CBD diameter nor predictive of the likelihood of choledocolithiasis.