AbstractPeriodontal disease is synonymous with the presence of periodontal pockets, and very often the clinical success of periodontal therapy is based on periodontal pocket depth reduction. Therefore, in the fields of periodontology and implant dentistry, significant research effort has been placed on the etiopathogenesis, diagnosis and treatment of periodontal/peri‐implant disease and as a consequence on pocket pathology. In this volume of Periodontology 2000, the in‐depth reviews include topics ranging from preclinical models, anatomy and structure of tissues, and molecular and bacterial components, to treatments of pockets around teeth and implants. These reviews aim to provide the readers with current and future perspectives on the different areas of research into the periodontal pocket.