Studying the relationship between hospital volume, surgical volume, and clinical outcomes, past research in part led to recommendations for volume-based referral as a safety practice. However, the volume–outcome relationship may be limited to selected surgical procedures, suggesting that systematic volume-based referral is unnecessary. This study further examines these relationships by evaluating the impact of hospital surgical volume on preventable adverse events. The latter were measured using the AHRQ Patient Safety Indicators (PSIs), which have noted limitations as measures of safety. Nevertheless, investigators found that hospital volume for abdominal aortic aneurysm, coronary bypass graft, and Roux-en-Y gastric bypass were inversely related to PSI rates. Additional research to further evaluate the structural and process differences between outcomes and hospital volume may help identify potential safety solutions.