Abstract. Blood samples were taken from Atlantic cod, Gadus morhua L., and several other marine teleost species in the northwest Atlantic Ocean to determine the prevalence of viral erythrocytic necrosis (VEN). The infection was found in G, morhua at a level of approximately 1.5° in the samples collected from both Newfoundland and Greenland. The latter finding extends the geographic range of VEN infection in this species. Ultrastructural details of the virus in erythrocytes of G. morhua from Greenland differed in several morphologic features from those previously reported.