Sibling relationships often involve exchanges of emotional and tangible support. When one sibling has a disability, the nature of the reciprocity of such support may differ from sibling pairs wherein no disability is present. Specifically, when an individual has autism, the nature of emotional and tangible reciprocity is unclear given the potential for a supportive or caregiving role of the sibling without autism. In this study, 256 adult siblings of autistic individuals completed a national survey. Analyses included descriptive statistics describing the nature of reciprocity and hierarchical regressions to identify the correlates of emotional and tangible reciprocity. Overall, participants often reported not giving or receiving much tangible support to/from their autistic sibling while they often gave and, to some extent received, emotional support from their autistic sibling. When the autistic sibling had more asocial behaviors, participants were more likely to provide emotional support than receive it. When participants engaged in more caregiving, they both gave and received more emotional and tangible support. Implications for research and practice are discussed.