This Book is about the various antibiotics that are being used in the treatment of periodontal diseases. It includes both systemically administered antibiotics and locally delivered antimicrobial agents. As we all know, Periodontitis has a plethora of organisms that affect the gingiva, PDL as well as the alveolar bone. A thorough knowledge of the microorganisms causing the disease can lead a practitioner to prescribing correct antibiotics taking into consideration their applicability, doses as well as their side effects.