BACKGROUND AND STUDY AIM: The aim of this observational prospective study was to evaluate the safety of outpatient therapeutic endoscopic retrograde cholangiopancreatography (ERCP) in a very elderly cohort.PATIENTS AND METHODS: A total of 600 patients were included in the study between June 2006 and June 2009. All underwent first therapeutic ERCP and were scheduled to be discharged on the same day following a postprocedure observation period of 6 hours. Of the 600 patients, 123 patients (group A) were re-admitted due to postprocedure complications that presented during the observation period, and 477 patients (group B) were discharged on the same day. Concomitant diseases, details of ERCP procedures, complications, and outcomes were all evaluated. The accuracy of the 6-hour postprocedure observation period, clinical criteria in predicting those patients aged 80 years and older in whom all therapeutic ERCP can be performed on an outpatient basis, and costs saved were all assessed.RESULTS: There was a statistical difference in incidence of concomitant diseases between groups A and B (group A 84.5 % vs. group B 74.6 %; P = 0.020). However, there was no difference between the groups with regard to indication for ERCP and type of intervention. There was no difference in postprocedure complication rate between very elderly patients and younger patients (< 80 years), except for prolonged sedation or hypotension, which occurred more frequently in older (≥ 80 years) than in younger (< 80 years) patients (7.6 % vs. 3.2 %; P = 0.037). In group B, complications necessitating re-admission after the 6-hour observation period occurred in 10 patients (2.09 %) (patients ≥ 80 years 0.8 % and patients < 80 years 2.5 %). The costs saved by performing the procedure on an outpatient basis was calculated as 150 € per patient.CONCLUSION: Outpatient therapeutic ERCP with postprocedure observation of 6 hours is a safe and cost-effective procedure in a significant proportion of very elderly patients.