Aim. In pedagogy, the topic of siblings is rarely explored. The environment of brothers and sisters is the first place in which an individual learns cooperation, mutual support, tolerance, and attitudes that are essential for functioning in adult life. The aim of this article is to present a research, whose objective was sibling relationships from the perspective of late adolescents, taking into account factors that are significant to them. Methods and materials. A survey study was conducted among young people aged between 18 and 23, therefore, people entering adulthood, with a research sample of 140 participants. The survey questionnaire examining family relationships consisted of closed-ended questions and open-ended questions, which gave respondents the opportunity to speak freely or justify their declarations. A part of the survey focused on relationships with siblings included questions about the meaning of having a sibling, its advantages and disadvantages, conflicts between siblings, and the role of parents in forming such a relationship. Results and conclusion. Based on the study, a conclusion may be drawn that although the modernisation processes affect the family structure and its functioning, young people perceive their siblings as friendly, supportive, and helpful, despite occasional annoyances. The respondents attribute considerable significance to shaping sibling relationships to their parents.