A total of 64 stranded cetaceans from the northeast USA and southeast Florida Gulf coastlines were sampled for bacteria during the period 1984 to 1990. Thirty-six individuals were dead when examined and 27 were alive but died shortly after stranding; one was released. Cultures were recovered from a variety of external and internal surfaces. Species of Vibrio were isolated from all Florida strandings; V. alginolyticus, V. parahaemolyticus, and V. damsela represented 35% of the total number of isolates (382). Vibrios were recovered from 10 individuals from the northeast; the 3 species above accounted for 17% of the total (139) and were most common from strandings between May and September. Other bacteria which represented greater-than-or-equal-to 5% of the total number of isolates in one or both areas included Edwardsiella tarda, Morganella/Proteus/Providencia spp., Pseudomonas putrefaciens, and other pseudomonads. Some geographical differences were noted.