This study is a secondary analysis of data gathered during baseline data collection prior to a cognitive-psychosocial-respite intervention provided in a randomized controlled trial (RCT). Content analysis was used to identify themes in parents' responses to an open-ended item about their perceptions of the effects on siblings of having a brother or sister who has either cancer or cystic fibrosis (CF). Of 91 themes tallied in the cancer group (n = 29), 74.5% reflected negative manifestations of increased risk in siblings, 1.1% no risk; and 24.2%, positive outcomes. Of 53 themes tallied in the CF group (n = 15), the same three categories had 67.9 %, 0%, and 32.1%, respectively. Contemporary life in these families portrayed in parents' descriptions not only validate the rationale for the RCT done, but also suggest the need in ambulatory pediatrics for intervention research on these vulnerable populations.