Implant periapical lesion (IPL) is an infectious-inflammatory alteration surrounding an implant apex. It is a multifactorial disease that may ultimately cause implant failure. The diagnosis of IPL is based on examination of clinical manifestations and apical radiolucency. Many etiologies have been attributed to IPL, including preexisting microbial pathology and surgical trauma. Moreover, many systems have been used to classify IPL based on different parameters. To date, non-surgical and surgical treatment, as well as removal of failed implants, have been considered to successfully manage IPL. However, prevention of IPL surpasses all modes of treatment. An increased number of IPL cases are expected as implants have become standard for tooth replacement in dentate arches. Therefore, it is necessary to understand IPL more comprehensively. Herein, an introduction to IPL, including its etiology, diagnosis, classification, treatment, and prevention, has been undertaken.