The present study investigated the effect of different bacterial species lipopolysaccharide plus Pseudomonas exotoxin A (LPS/PEA) on the induction of multiple organ injury (MOI). Rats were injected with various LPS from Salmonella (SAE, SAT), E. coli (EB4, EB5), or P. aeruginosa (PAL) and PEA showed a greater mortality in the SAE/PEA and SAT/PEA groups. Histological alterations, serum enzymes, and cytokines changes were severer in the SAE/PEA group than the EB4/PEA or PAL/PEA group. EB4/PEA and PAL/PEA failed to induce MOI, even at the LPS doses increased up to 2-4- and 4-8-fold, respectively. Rats co-treated with Salmonella lipid A/PEA developed severer MOI than the E. coli lipid A/PEA. The results indicated the critical roles of MOI induction, which were related to LPS derived from appropriate bacterial species.