Fibrocalculous pancreatitis diabetes (FCPD), a late stage of tropical chronic pancreatitis (TCP), is classified as a secondary cause of diabetes mellitus resulting from pancreatic exocrine dysfunction. The distinctive features of FCPD and TCP are young age at onset, presence of large intraductal pancreatic calculi, and reported mainly in tropical developing countries. Their etiology is still obscure, but the autodigestion due to aberrant intraductal activation of zymogens by trypsin is thought to be a primary common event. Recently, mutations in SPINKI gene encoding a pancreatic secretory trypsin inhibitor have been reported in association with an increased risk of pancreatitis. We describe a heterozygous mutation, IVS3+2 T>C, of SPINK1 gene in a young Thai female patient with typical presentation of FCPD. To our knowledge, this is the first report of the SPINK1 gene mutation in a FCPD patient in Southeast Asia.