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.