Background: ERCP and EUS are both considered technically advanced and time-consuming procedures. A large prospective comparison of the professional work involved in performing these procedures has not been described. Methods: Consecutive ERCP and EUS cases from 12 endoscopy centers from 8/99-10/99 were studied. Data captured included indications for procedure, sedation time, scope time (from insertion to removal), number of instruments/accessories used, medications, post-procedure MD interpretation and consultation time, recovery time and complications. Comparisons were made using Student's t-test, chi-square, ANOVA and Tukey-Kramer. Results: 2,392 ERCP (1158M/1234F) and 1,882 EUS (1125M/757F) procedures were analyzed. EUS patients were significantly older than ERCP patients (mean age 62 vs 58 p<.0001). Total scope time was significantly longer with EUS compared to ERCP (60.4 ± 0.8 vs 51.8 ± 0.6 min). Further analysis (11 centers) was performed on 732 procedures (295 ERCP/437 EUS). Sedation time was similar (EUS 14.9 min vs ERCP 12.7 min), however, post-procedure MD time for interpreting images and consultation (reviewing results) were both significantly longer with EUS procedures (see table). Thus, the total average MD time to perform an EUS was 22% greater than ERCP (95.7 min vs 78.5 min). There were no differences in recovery time or major complications. EUS utilized more scopes, while ERCP utilized more accessories. EUS for pancreatic dx/staging was most time consuming (scope time 64.6 min) compared to esophageal, gastric, and rectal EUS cases (45.9, 44.2, 47.5 min, respectively; p < 0.05 for pancreatic vs esophageal). Therapeutic ERCP was significantly more time consuming than diagnostic ERCP (47.2 vs 38.8 min). Conclusions: EUS procedures require greater physician “work” than ERCP. This information may be helpful in determining space, time and reimbursement allocations.