Iatrogeny — undesirable effects of medical interventions, which can be caused by errors in the choice of therapy, insufficient qualification of specialist and incorrect compliance with technic of procedures. The increasing popularity and availability of cosmetological treatments are accompanied by a growth in the number of iatrogenic complications. Iatrogenic complications in cosmetology have a significant impact on patients’ psychological state. Physical discomfort associated with complications is often followed by psychological problems: reduced self-assessment, feelings of self-doubt, depressive disorders, social isolation. Post-inflammatory hyperpigmentation (PIH) is a common form of iatrogenic hypermelanosis that occurs after cosmetological procedures. Treatment of PIH requires a comprehensive approach, including the use of photoprotectors and topical agents. The article lists the pathogenetic aspects of PIH, as well as provides external correction agents such as hydroquinone, azelaic, tranexamic, kojic acids, retinoids and thiamidol. Thiamidol is a highly selective human tyrosinase inhibitor, the application of which reduces the risk of PIH development. The presented clinical cases confirm that the irrational use of hardware technologies and the lack of a comprehensive approach affecting all the parts of melanogenesis contribute to the development of iatrogenic complications. Effective application of safe methods, which contribute to the elimination of iatrogenic post-inflammatory hypermelanosis, is an urgent task of improving the quality of life of patients.