Enhanced availability of implantoprosthetic therapy and wider indications have resulted in a large number of inserted implants on a yearly basis. Consequently, the prevalence of periimplant diseases has increased, caused by numerous factors, such as poor oral hygiene, untreated periodontal disease, smoking, residual cement, malocclusion, keratinized mucosa and other iatrogenic factors. Peri‐implant mucositis is defined as an inflammation of soft tissues, while peri-implantitis is defined as a loss of soft and hard tissues and bones. Keeping these inflammatory diseases stabile is of great importance to clinicians for long-term results in implant therapy. Current approach, following scientific evidence in peri-implant disease therapy, is like the one to the therapy of periodontal diseases, infection control and prosthetic correction, in order to establish proper oral hygiene, to remove plaque and calculus, as well as biofilm. Surgical approach, resective or regenerative periodontal therapy are applied depending on the defect configuration, in order to try to save the implants affected by peri-implant diseases. Lately there has been an increased use of diode lasers for photodynamic therapy and implant surface disinfection. It is important for clinicians to be well acquainted with aetiology, pathogenesis and microbiological characteristics of peri-implant diseases, so that they could make a diagnosis and carry out targeted treatment.