PURPOSE: The purpose of this study was to compare rates of ultrasound (US) and computed tomography (CT) for suspected appendicitis at hospitals able to provide definitive surgical care with those from their associated referral hospitals. METHODS: A retrospective cohort study of children undergoing appendectomy using the Pediatric NSQIP Appendectomy Pilot Database (1/1/2013-8/31/2014) was performed. Imaging rates at the initial hospital of presentation were compared between groups after adjusting for differences in demographic characteristics. RESULTS: We identified 4859 patients from 28 definitive care hospitals, of which 35% underwent diagnostic imaging at a referral hospital prior to transfer (range: 20.3-70.4%). The overall odds of receiving a CT scan was 10.9-times greater (95% CI: 9.4-12.5) at referring hospitals compared to definitive care hospitals, and the odds were significantly higher for referral hospitals in 96% (27/28) of the geographic regions represented. The overall odds of an initial attempt at US prior to CT was 11.1 times greater (95% CI: 9.09-14.28), and the odds of receiving any ultrasound was 6.25-times greater (95% CI: 5.26-7.14) at definitive care hospitals compared to referral hospitals. CONCLUSIONS: Children initially evaluated for suspected appendicitis at referring hospitals are much more likely to receive a diagnostic CT, and those imaged with CT are much less likely to receive an US as the initial diagnostic test.