In an ongoing prospective study involving ERCP in a wide spectrum of practice settings, we are examining technical success and complication rates, and their relative impact on utilization of resources. METHODS: Consecutive ERCP's attempted at 11 centers (6 private, 5 university) were enrolled. Procedure data were recorded at time of ERCP, and outcomes assessed at 30 days. Complications were defined by consensus criteria (Cotton et al), but included all procedure-related events. ERCP-related hospital days (=hosp-days) were defined as nights in hospital for observation, treatment of complications (=complic's), or for additional unplanned endoscopic, radiological, and surgical interventions due to failures or complic's of ERCP (=addt'l proc). RESULTS: Data are shown for the 486 cases (of 804 ERCP) which were performed on "virgin" papillae (no prior sphincterotomy or stent) and were done for "traditional" indications (Dx or biliary Tx only, without pancreatic sphincter or ductal Tx). "VIRGIN PAPILLA" ERCP (n=486) Diagnostic intended only (n=142) Technical Success Complete 86% Partial 8% Fail 6% Success 86% 8% 6% Complic's 6% 0% 22% Addt'l proc" 2% 18%* 22%* Hosp-days 0.8 ± 0.2 0.5 ± 0.2 3.6* ± 1.9 Biliary therapy intended (n=344) Technical Complete Partial Fail Success 87% 5% 8% Complic's 14% 17% 12% (n=344) Addt'l proc 4% 44%* 62%* Hosp-days 1.5 ± 0.1 2.7 ± 1.0 6.2* ± 1.8 *P<0.01 vs complete CONCLUSIONS: For both Dx and Tx ERCP, complication rates were similar regardless of whether ERCP was a technical success or failure. However, failed ERCP resulted in a marked excess of unplanned endoscopic, radiological, and surgical interventions, and significant prolongation of hospital stay (about 4 days). Resource utilization related to ERCP is primarily related to technical success.