Genetic factors are increasingly found as potential causes of children with acute recurrent pancreatitis (ARP) or chronic pancreatitis (CP). Representative genes include cationic trypsinogen, serine protease 1 (PRSS1), serine protease inhibitor Kazal type 1 (SPINK1), cystic fibrosis transmembrane conductance regulator (CFTR), chymotrypsin C (CTRC) and calcium sensing receptor (CASR) genes, etc. In Korean children, PRSS1 and SPINK1 genes have been most commonly studied, while CFTR mutations were reported in one patient to date. We report a case of a 13-year-old male adolescent with CP with CFTR mutations. Since he was first diagnosed with idiopathic acute pancreatitis (IAP) based on laboratory and computed tomographic findings, he was admitted with ARP and CP over four times in a year at the secondary and tertiary hospital. No etiology was detected by several examinations including magnetic resonance cholangiopancreatography (MRCP), endosco-pic retrograde cholangiopancreatography (ERCP), endoscopic ultrasonography (EUS) with fine needle aspiration (FNA) biopsy and genetic test including PRSS1 and SPINK1. Although he had no typical symptoms associated with cystic fibrosis (CF), CFTR mutations were detected with additional gene examination. Testing for CFTR mutations should be concerned in pediatric patients with APR and CP without other identified causes.