To determine possible functions of the Edwardsiella ictaluri plasmids, pEI1 and pEI2, we analyzed the sequence of both plasmids. Plasmid pEI1 is 4807 bp, with 51% G + C, and 23 possible open reading frames of 40 amino acids or greater. Plasmid pEI2 is 5643 bp, with 51% G + C, and 24 possible reading frames. Database searches indicated that pEI1 contains an insertion element and a ROM analog. In addition, pEI1 possesses an open reading frame with strong homology to SlrP, SspH1, and SspH2 of Salmonella typhimurium and IpaH of Shigella flexnari, which have leucine-rich repeat regions and are components of type III secretory systems. pEI2 has a frame with weak homology to Spa15 of S. flexnari 5 and InvB of S. sonnei and S. typhimurium, which are also type III secretory system components, three origins of replication, a Rep analog, and a multimer resolution site.