There are several microbiological and immunological aspects involved in the interactions between bacteria and the host during the initiation and progression of periodontal disease. Periodontal therapy lacks the diagnostic capability to tailor predictable therapy for the individual. An understanding of the various mechanisms involved will enable us to plan better therapeutic approach that aims in the eradication of the disease process. In future, we can improve the host__ampersandsignrsquo;s ability and thereby prevent the colonization of harmful periodontal pathogens. This review article provides the current state of the art in regard to bacterial host cell interactions that take place during periodontal disease pathogenesis