Six species of bacteria (family Enterobacteriaceae) not commonly reported as associated with disease in American alligators (Alligator mississippiensis) were documented, suggesting that Aeromonas is not the only bacterium responsible for septicemia in crocodilians. These included Citrobacter freundii, Enterobacter agglomerans, Proteus sp., Morganella morganii, Serratia marcescens, and Klebsiella oxytoca. Clinical signs of disease included intensive basking, anorexia, lethargy, flaccid limb paralysis, stomatitis, and dermatitis. Our data indicated that early treatment with broad-spectrum antibiotics was preferable to waiting for sensitivity results.