To determine if pancreatic necrosis is a communicable disease of trout, lots of eyed brook trout eggs were obtained from four hatcheries. Pancreatic necrosis appeared spontaneously in trout from one of these hatcheries and the other strains were exposed to infection by suspension prepared from diseased fish. In all cases, typical pancreatic necrosis appeared in fish exposed to infection and the control fish remained healthy. Disease was more acute in fry fed brine shrimp nauplii than in those fed beef liver. Mortality data suggest that susceptibility to pancreatic necrosis decreases with the increased age of trout. No treatment for the disease is known, but sanitary measures were effective in preventing its spread.