Abstract: A total of 150 P. multocida isolates from HS cases obtained from Veterinary Diagnostic Laboratory, Petaling Jaya were reconfirmed of their biochemical characteristics. Plasmid DNA profiling and Agarose gel electrophoresis were carried out as described recently (Salmah, 2004) to determine size, number and profile of plasmids for each isolate. Plasmids detected were 100% in all P. multocida isolates with identical profile of 2 plasmids size 3.0 and 5.5 kb. No large plasmids could be detected in all isolates. Only 4 of 30 REs were found to cleave these plasmids with identical restriction fingerprints – BglII, HaeIII, RsaI and SspI. From RE analysis results obtained, it can be concluded that the plasmid DNA in serotype B isolates are identical. The finding of this preliminary study will help to further investigate whether any of these plasmids are related to virulence mechanism (pathogenicity) of P. multocida.