We report localization of the gene for autosomal dominant hereditary pancreatitis (HP) to a small region of the long arm of chromosome 7 in a large four-generation kindred. Affected family members may first become symptomatic in childhood or even infancy with progression to pancreatic calcification, pseudocyst formation, endocrine and exocrine insufficiency, and even pancreatic cancer in some cases. However, obligate gene carriers may remain virtually symptom free throughout life. HP is the most common cause of childhood pancreatitis in the United States. Gene mapping with microsatellite markers demonstrates that HP is tightly linked to the marker D7S684 (Zmax = 7.0, theta = 0.0). Three obligate recombinants place the HP locus within a 16-cM interval between markers D7S495 and D7S688. This confirms the localization of HP to 7q reported in a separate French kindred (2).