Introduction The term sex education is used very differently both in popular usage and in professional contexts. However, scientific and professional discourses need terms that are as unambiguous as possible. The article defines sexuality education as a scientific discipline, differentiates for the first time between theories of science and action as well as sexuality education practice, justifies why modern sexuality education should also be developed against the background of emancipatory epistemological interests and provides an insight into Anglo-American literature. The discipline of sexuality education is currently still in a process of discovery, which was stimulated, among other things, by contributions in the discussion section of this journal. The target groups are the growing group of practical and conceptual professionals as well as those interested in research and theory in the broad field of sexuality education. Objectives At the beginning, the understanding of sexuality education as a sub-discipline of educational science with references to sexuality science is justified. This is followed by a confrontation with the discourse on the concept of emancipation in science and social theory. The current instruments of critical-reflective educational science are referred to as a "grammar of scientific discourse", in relation first to scientific methodology and then to theories of action in sexuality education and sexual education. An outlook focuses on future perspectives and the international discourse space. Methods The article chooses a critical-hermeneutic approach and draws on primary and secondary literature from the fields of science and social theory, education, and sexuality studies as well as the educational sub-disciplines of social and sexuality education. Results The subject area of sexual education encompasses sexual learning, educability, and the need for education, as well as the sexual image and need for education of human beings, including the corresponding professional fields of teaching, education, and training. This makes it obvious that educational science should be understood as a reference discipline with sexual science as the most important neighboring discipline. Emancipation as both a concept and an interest in knowledge is still valid today as a normative orientation for all scientific endeavors that are interested in human maturity and self-determination, and therefore also for sexual education. The methodological and ideology-critical criteria of critical-reflexive educational science also guarantee the discipline its scientific autonomy. Conclusion As a scientific meta-theory, sexuality education needs the educational science and the neighboring discipline of sexuality studies with an emancipatory interest in knowledge and critical-reflexive methodology. An elaborated theory as well as an international positioning are, however, still lacking.