This paper discusses the concept of ‘children at risk’ for poor educational outcomes from a sociological perspective. The broader concept of social inequality with its determinants and dimensions is introduced as a conceptual basis. The concept of ‘children at risk’ for adverse educational outcomes can be located within this framework: They are defined as children with an above-average risk of unfavourable educational outcomes because of their affiliation to a social category. The unequal distribution of educational outcomes between different social categories is a well-established research topic in sociology which is usually simply referred to as ‘educational inequality’. Its description and especially its explanation are the major tasks for sociologists in this field. The paper provides some selected examples for educational inequalities and introduces one exemplary theoretical explanation from a sociological perspective for this phenomenon. Furthermore, the concept of ‘children at risk’ is critically discussed in light of the usefulness as well as the complex of problems that may be associated with its application in sociology.