Heat shock protein (HSP) is one of cellular protein commonly present in major periodontopathogenic bacteria as well as mammalian cells. The protein may play a role in the immunopathogenesis by modulating autoimmune reaction due to its high level of sequence homology between bacteria and human counterpart. Hence, identifying immunodomiant epitope of bacteria HSP that is cross-reactive to periodontopathogenic bacteria with a specificity to human HSP may comprise a critical strategy for development of a periodontal vaccine. The present study was performed to establish clones producing monoclonal antibody reactive to Porphyromonas gingivalis (P. gingivalis) HSP with a specificity to human HSP. 4 different hybridomas were cloned producing monoclonal IgG antibodies to P. gingivalis HSP and evaluated for their reactivity and specificity to other periodontopathogenic bacteria as well as to human HSP. These four monoclonal antibodies reacted with P. gingivalis HSP only with specificities to other bacteria tested and human HSP as well. The antigenic epitopes producing the 4 monoclonal antibody may be potentially developed as vaccine candidates. Further investigations are under way to identify more clones producing monoclonal antibodies reactive to P. gingivalis HSP and to other periodontopathogenic bacteria as well, while maintaining specificities to human counterpart.