We report the identification of a novel mutation in the protease serine 1 (PRSS1) gene in a hereditary pancreatitis (HP) family. Relevant clinical data were collected in this 24-member family. Moreover, the PRSS1 gene was amplified from the genomic DNA of the members with pancreatitis. The amplified products were analyzed by sequencing. A cytosine (C) to thymine (T) mutation in PRSS1 exon3 was detected in four affected members. This novel PRSS1 mutation may be an important factor associated with HP.