Siblings have unique relationships; however, not all sibling relationships are typical. In North America, the preterm birth rate ranks second only to Africa in a global climate of rising preterm birth rates. A paucity of literature exists for sibling relationships when one sibling is born prematurely. In this hermeneutic phenomenological study, we explored the lived experience of adult siblings with prematurely born, young adult brothers and sisters who subsequently developed disabilities. The 28 siblings, interviewed with open-ended questions, represented 47 families with extremely-low-birth-weight young adults with neurodevelopmental disabilities born between 1977 and 1982. Existential reflection guided by van Manen’s human science approach assisted the analysis of tape-recorded conversations. A structure of meaning entitled “outside looking in” emerged to illustrate the extraordinary relationships forged by the adult siblings with their brothers and sisters throughout their years together.