Human sexuality is a dynamic and complex reality, inseparable from a man and woman, whose beings completely imbues. By it, which is a God's gift, human is capable of bestowing himself to another, as well as accepting that gift.Just like this constitutive element of the human person, sex education is one dimension of integral human education which can't be separated from him. Education, in general, implies a process that leads from human's creation to a fulfillment of humanity and segregation of sex education would mean human's impoverishment and betrayal.Following many European countries, where it's actively carried out, sex education was also echoed in Republic of Croatia, where it was implemented into curriculum by force. That forced implementation tried to impose it's point of view on citizens, asserting completely unacceptable views about sexuality, marriage and family, which are opposite to christian anthropology and Croatian national being. Ideological background of Sex Education, that's taught in elementary and high schools, consists of sexology and gender ideology, on which they are based on and mentioned in this work, controversial initiatives. According to sexology, all sexual behaviors are ethically equally acceptable, while the term gender, that most people haven't heard of, is succesfully wrecking the foundation of a human being, destroying traditional role of a man and woman in the society.Sex education is still carried out in elementary and high schools despite causing before mentioned altercations and violations of Constitutional and Law regulations, as well as International Treaties.