Peri‐implant diseases, including peri‐implant mucositis and peri‐implantitis, were first defined and described at the First European Workshop on Periodontology in Ittingen in 1993. Following this, there have been numerous workshops addressing the definition, prevalence, and treatment of these diseases. Peri‐implant mucositis is considered to be the precursor of peri‐implantitis. The objective of this narrative review was to address key questions related to peri‐implant mucositis, including: 1) the definition of peri‐implant mucositis, 2) conversion of peri‐implant health to the biofilm‐induced peri‐implant mucositis lesion, 3) reversibility of peri‐implant mucosits, 4) the long‐standing peri‐implant mucositis lesion, 5) similarities and differences between peri‐implant mucositis at implants and gingivitis at teeth, and 6) risk indicators/factors for peri‐implant mucositis.