Retrograde peri-implantitis (RPI) is a primary microbial inflammatory condition that affects only the apical portion of an osseointegrated implant, which retains normal bone-to-implant contact in its coronal portion. Currently, no uniformly accepted definition or classification exists for RPI. This article reviews the etiopathological mechanisms, diagnostic pattern, and current treatment modalities for this type of periapical implant bone loss. The prevalence of RPI is reported to be relatively low, and along with a lack of an accepted classification system there is no widely accepted treatment algorithm. Therapeutic options include antibiotics, open-flap implant debridement, and apical resection eventually including apicoectomy of endodontically affected adjacent teeth, with or without bone grafting or removal of the affected implant. Implants with RPI usually remain osseointegrated. A diagnostic approach is proposed to establish the staging of the lesion and determine the best treatment option accordingly. When there is no loss of implant stability the most adequate treatment in the acute and chronic stage is apical resection of the implant with regeneration of the bone defect. If there is implant mobility, extraction of the implant is necessary.