Background: Cockroaches have important role in transmission and distribution of pathogen agents. So, this study was carried out to determine the cockroaches' species and their bacterial agents in Kashan hospitals in 2001.

Materials and Methods: This description study was performed on 88 cockroaches of three major medical centers. Species of cockroaches, their bacterial infection, and isolated bacteria species from internal and external surface were determined. The frequency of infection in cockroaches was determined and their prevalence in cockroaches' population was estimated.

Results: From 88, 83% were German cockroaches and remaining were American cockroaches. The rate of infection was 44.3%. 61.5% of German cockroaches and 100% of American cockroaches were infected with at least one species of bacteria. Internal and external infections of cockroaches were 71.8% and 28.2%, respectively. The most prevalent bacterium was Enthracoccus (36%) and Streptococcus (31%) respectively. Naghavi hospital had more infection (76%) compare to others. Bacteria isolated form internal and external levels were Streptococcus, Escherichia coli, Bacillus, Enterococcus, Micrococcus, Coagulase-Negative Staphylococci, Coagulase-Positive Staphylococci, Pseudomonas.

Conclusion: Cockroaches bacterial infection is a noteworthy problem in Kashan hospitals. Therefore it is considered the ways to reduce abundant cockroaches and their bacterial infection..