Periodontal diseases are biofilm-mediated, chronic infectious diseases and are the most common cause of tooth loss in the modern world. Periodontitis involves a complex interaction between environmental (such as specific bacteria) and host (genetic and immunological) factors that leads to loss of periodontal attachment apparatus. Nonsurgical periodontal therapy (NSPT) is the cornerstone of periodontal therapy and the first recommended approach to the control of periodontal infections. Nonsurgical therapy aims to eliminate both living bacteria in the microbial biofilm and calcified biofilm microorganisms from the tooth surface and adjacent soft tissues. Complete elimination of such pathogenic microorganisms is perhaps over-ambitious. However, a reduction in inflammation of the periodontium due to a lesser bacterial load leads to beneficial clinical changes. The aim of present review of literature is discuss the nonsurgical periodontal therapy in detail.