Background Endoscopic ultrasound (EUS) is useful in the diagnostic workup of idiopathic acute pancreatitis but its role as a predictor of recurrence has not been thoroughly assessed. Our aim was to study the performance of EUS in idiopathic acute pancreatitis, its impact on the natural history of the disease, and the factors related to recurrence. Methods Patients with idiopathic acute pancreatitis referred to our endoscopy unit were enrolled and followed, with assessment of the performance of endoscopic retrograde cholangiopancreatography (ERCP), cholecystectomy, and the incidence of recurrence. EUS findings and recurrence rates were compared between patients with a first episode or recurrent attacks and in patients with previous cholecystectomy versus those with gallbladder in situ. Results One hundred six patients were included (mean follow up: 53.59±27.79 months). Biliary disease related to stones was the most common finding on EUS (49.1%), and patients referred for recurrent attacks showed the highest recurrence rate during follow up (57.1%). ERCP or cholecystectomy reduced recurrences to 14.3% in patients with biliary disease. Age under 65 (odds ratio [OR] 3.56, 95% confidence interval [CI] 1.21-10.44; P=0.02), previous cholecystectomy (OR 3.19, 95%CI 1.11-9.17; P=0.03), and no lithiasis on EUS (OR 2.87, 95%CI 1.04-7.87; P=0.04) were independent risks factors for recurrence. Conclusions EUS-directed ERCP/cholecystectomy was associated with lower relapse rates in idiopathic acute pancreatitis. Along with age and gallbladder status, it provides predictive information about recurrence likelihood.