This document discusses the anatomy, histology, and clinical significance of the attached gingiva. It defines attached gingiva as the portion of gingiva firmly bound to the underlying alveolar bone. The normal width of attached gingiva is described to be greater in the anterior regions. Inadequate width is associated with increased risk of recession and plaque formation. Methods for measuring width and increasing width through surgery are presented. The importance of keratinized tissue for protection and force distribution is explained.