Abstract: Periodontitis is a chronic infectious disease which can cause the destruction of tooth-supporting structures. It is acknowledged that periodontitis is the leading cause of tooth loss in adults. Recently, emerging evidence suggests that periodontitis can elicit systemic inflammation and adaptive immune response through subgingival microorganisms in the dental biofilm. Hence, periodontitis has been recognized as a potential risk factor contributing to a wide range of systemic diseases. Although the detailed biological mechanisms are still not fully understood, some available studies strongly suggest that a bidirectional link exists between periodontitis and systemic diseases. Both conditions can affect and aggravate each other. This article attempts to summarize the impacts of periodontal disease on systemic diseases and health