Individual’s experiences with social relationships across adolescence, young adulthood and particularly during formative years in childhood are of substantial value in the context of well-being and health. Various scholars have researched the influence of parent and peer attachments on romantic relationships; however, little is known about the role siblings play in romantic relationships. A nation-wide survey in Aotearoa reported that 60% of families with children have more than two children (Statistics NZ, 2020). Accordingly, this research examined the links between sibling attachment, parental attachment, and romantic relationship quality. 151 students aged 18 or older, from the psychology department at the Auckland University of Technology answered an anonymous survey which explored their attachment with their parents, and siblings in childhood, and romantic partners in adulthood. Results from the data analysis reported sibling attachment to be the strongest predictor of romantic quality. In comparison, maternal attachment was a stronger predictor of romantic relationship quality, than paternal attachment. Furthermore, findings from the path analyses revealed that sibling attachment mediated the impacts of parental attachment on the quality of romantic relationships. Some of the study limitations included the sample being small and female dominated; however, recommendations for future research were discussed. Overall, the current study contributes to understanding how sibling attachments influence parental attachment impacts on romantic relationships, and highlights how attachments with various family members in early life plays into their romantic relationships. This research hopes to facilitate an exciting direction for future research around sibling and parental attachment.