Sexuality education for school-aged young people is a crucial component of all quality education systems. It prepares young people for participation in society as responsible, mature and community-minded citizens. Most contemporary school education curricula generally aim to enhance young people's knowledge, skills and understandings of the world, and of their rights as human beings and citizens of nations. The current sexuality problems of many young people are the opposite of these; namely, ignorance, lack of skills, misunderstandings, and loss of rights, as well as unnecessary fear and shame about themselves and others. Many young people do not receive any sexuality education at all, and frequently parents have been found to be unsatisfactory providers of sexuality education for their offspring. Schools, then, become the logical place to provide this. Nowadays, the earlier maturing of girls and boys provides a further persuasive argument for quality sexuality education in all schools. The absence or erosion of school-based sexuality education through ignorance, fear or unreasoned response helps support ignorance about sexual behaviours, increased rates of unwanted pregnancy, sexually transmitted infections, and the cruel loss of life opportunities for young people. The present paper responds to 12 parental objections to school sexuality education, by providing research facts and evidence-based reasoned arguments to them.