Stigmatization and discrimination of people due to their specific characteristics is a widespread problem, both in Poland and worldwide. Stigmatization of people with mental disorders and diseases is a particular type of it. Although this phenomenon has its roots in Antiquity and the Middle Ages, and was scientifically described several dozen years ago, it is still a current and unsolved problem. Stigmatization can take place on different levels and appear as autostigmatization, community-related stigmatization, and institutional stigmatization. It takes different forms and has varying negative effects. Counteracting this situation and eliminating its effects, that have already arisen, is a vital necessity and an essential activity of the society in order to provide better functioning and treatment for people with mental illness. Challenges in this area are faced both by state institutions responsible for the health care system and by private entities such as NGOs, media corporations, and companies employing people. The individual commitment of each and every person is also important to prevent and respond appropriately to the stigmatization of people affected by mental illness.