Listeria monocytogenes cultures isolated from a variety of seafoods were subjected to phage typing procedures utilizing the French International set of L. monocytogenes bacteriophages. These cultures were also subjected to the activity of newly isolated North American phages to L. monocytogenes. There were 147 serotype 1/2 and 80 serotype 4b L. monocytogenes cultures isolated from 16 varieties of marine products included in this study. L. monocytogenes was most frequently isolated from crab meat, salmon, and shrimp. Bacteriophages to serotype 1/2 isolates most frequently observed as single patterns were 575, 1967, 2685, and 19. Serotype 4b phages observed most frequently were 1317, 2425, and 52 as single phage patterns, and 52/340/110/108/2671/2425/2389 and the new North American phages 90861/910716/93253/90666 as one complete spectrum. The prevalence of L. monocytogenes and their respective phage spectra observed in the 16 varieties of seafoods studied is discussed.