In several developmental theories, separation anxiety has been identified as an important feature of close interpersonal relationships. Most often, separation anxiety has been examined in the context of mother-child dyads in infancy. Increasingly, however, it is recognized that separation anxiety is also relevant in other relationships (e.g., the father-child relationship) and in later developmental periods (e.g., adolescence and emerging adulthood). The present study aimed to investigate separation anxiety at the family level in families with emerging adults. By using the Social Relations Model, we aimed to determine the extent to which the actor, the partner, their specific relationships, and the family contribute to separation anxiety in dyadic family relationships. A total of 119 Belgian two-parent families with an emerging adult participated in a round-robin design, in which family members reported on their feelings of separation anxiety toward each other. Findings showed that separation anxiety can be represented as a personal characteristic (i.e., an actor effect) and as a specific feature of the mother-child dyad. Further, findings indicate that separation anxiety is also characteristic of the father-mother marital relationship and of the family climate as a whole. Implications for the meaning of separation anxiety and clinical practice are discussed.