Summary: This article examines, in the light of Christian anthropology, and in the perspective of ethics, certain questions concerning the affective-sexual life of persons with mental disability. It holds, most fundamentally, that there cannot be one sexuality for all other persons and a different one for those with mental disability – even though the concrete conditions for the exercise of human sexuality necessarily differ. Particular attention is paid to the matter of sterilisation of the mentally disabled, and to that of protecting them from sexual violence. The importance is underlined of a collective commitment in behalf of the respect due the fundamental human rights of these persons.