Emphasis has been placed on the importance of obesity as a predictor of poor outcome from acute pancreatitis. The aim of this study was to determine whether obesity confers an increased risk and severity of post-ERCP pancreatitis. METHODS: A 160 variable database was prospectively collected by a defined protocol on patients undergoing diagnostic or therapeutic ERCP and participating in a randomized controlled trial evaluating whether prophylactic corticosteroids will reduce the incidence of post-procedure pancreatitis. Data were collected at the time of the procedure, prior to and after discharge. Standardized criteria were used to diagnose and grade the severity of post-procedure pancreatitis (GI Endosc 1991;37:383). Mild pancreatitis required 2-3 days of hospitalization; moderate pancreatitis required 4-10 days; severe pancreatitis required >10 days or surgical/invasive radiologic intervention or was associated with a complication. A body mass index (BMI) >30kg/m2 is generally regarded as obese (National Academy of Sciences) and was used as the cutoff point in this study. RESULTS: 935 patients were entered into the study. Pancreatitis occurred in 139 patients (14.9%) and was graded mild in 93 (9.9%), moderate in 38 (4.1%), and severe in 8 (.9%). Data on BMI were available on 791 patients (84.6%). There was no statistically significant association between the presence of obesity and the development of post-ERCP pancreatitis (p=0.143). There was no association between obesity and the severity of the pancreatitis (p=.381). The following table displays the mean BMI for each level of pancreatitis severity. Grade of Pancreatitis N Mean BMI None 671 26.75 Mild 82 25.78 Moderate 35 25.03 Severe 3 33.09 There was only a marginal relationship between BMI and severity of pancreatitis (p= 098). CONCLUSIONS: 1) Obesity did not seem to confer an increased risk for post-ERCP pancreatitis. 2) There was no statistically significant association between obesity and the severity of post-procedure pancreatitis. 3) There may be a weak relationship between BMI and the severity of pancreatitis. 4) This study is ongoing.