Hereditary pancreatitis is an autosomal dominant disease characterized by recurrent episodes of pancreatitis, often beginning in childhood, with a positive family history involving at least two other affected family members with no known other precipitating factors. Most forms of hereditary pancreatitis are caused by one of two common mutations, i.e., R122H in exon 3 and N29I in exon 2 of the cationic trypsinogen (CT) (PRSS1) gene, located on chromosome 7. The authors describe the case of a 15-year-old boy who had suffered from recurrent attacks of pancreatitis since age three. His mother and grandmother had chronic pancreatitis and diabetes mellitus. Mutation analysis was performed on the family due to the suspicion of hereditary pancreatitis. The CT gene was analyzed in DNA samples extracted from the peripheral blood of three family members, the mother, the proband, and the proband's sister. Two members of the family, the mother and the proband, were found to have a N29I mutation in the CT gene. The authors document the first family with hereditary pancreatitis associated with the N29I mutation in Korea.