Mental incapacity as an institute of criminal law indicates overall biological-psychological basis for exclusion of culpability, thus generally excludes her/him from the criminal law itself. The position of the abovementioned sensitive group has changed since the first social communities. In the last hundred years, by adoption of numerous international acts guaranteeing universal human rights, the ethical attitude of society towards them has been raised to a higher level. At the national level, the Constitution guarantees fundamental rights and forbids discrimination on all grounds and the Criminal Code acquits mental incapable persons from their guilt, so the status of these persons has been covered by the Protection of Persons with Mental Disorders Act. Although the position of mental incapable persons is well described in numerous legal acts, these persons’ fundamental human rights are often violated by the actions and decisions of govermental bodies, as testified by litigations at highest national judicial bodies as well as at the European Court of Human Rights. Research of jurisprudence characteristics confirmed the vulnerability of mentally incapable persons in proceedings against them as well as their low level of familiarity with the available mechanisms for protection of their fundamental human rights.