Medically important bacteria were extracted from their outer surface of bodies by standard procedures. Results: Culturing outer surface wash of cockroaches resulted in the separation of Klebsiella, Pseudomonas, Escherichia coli, Staphylococcus, Proteus and Streptococcus. The main common bacteria were Klebsiella (35%) and Pseudomonas (30%). Also, results of culture media showed that about 90% of cockroaches infected to at least one bacterium.