Most research investigating relationships during emerging adulthood has focused on the quality of friendships and romantic relationships while devoting little attention to family relationships. The present study considered the quality of attachment to both parents in a sample of 253 emerging adults, aged 20–31 (M = 24.32; SD = 2.22), examining how these could influence the quality of sibling relationships and analyzing the link of these family relationships with the level of life satisfaction. Results showed that the attachment to both the mother and the father was linked to the quality of sibling relationships. Moreover, parental attachment to both parents and sibling relationships affected the level of perceived life satisfaction during emerging adulthood. Limitations, strengths, and theoretical and clinical implications are discussed.