The current study aimed to explore the impact of the social deficits typical of autism on the adult sibling relationships. The study obtained the personal perspectives of five adults with a brother/sister with autism and learning disability who lived in the greater Dublin area. In order to isolate this effect from those related to the associated learning disability, a comparison group of five siblings of adults with Down syndrome or other non specified learning disability was included. The perspectives gathered ranged from the experiences of growing up with a child with disability through to predicted care involvement. The personal accounts were collected using a qualitative semi-structured interview and adult sibling relationship measurement. The data was analysed for recurring themes and relationships. The researcher discovered that there are too many complex interlocking factors that influence the adult sibling relationship including past experiences, parental attitudes and expectations, other family commitments, gender and geographical proximity. In the context of any learning disability, the adult sibling relationship was confirmed as being less egalitarian or reciprocal and that the sibling bond is more salient and active than for typically developing adult sibling relationships. Finally, the central assertion that sibling relationships were hampered by autism was inconclusive. However, the participants were very positive in their descriptions of the social skills of their sibling with autism. Further investigation into this area is required.