This descriptive, exploratory study investigated the social support interventions received by siblings of children with cancer and which of those interventions are perceived as being helpful. A comparison between the sibling's perceptions and their parents was made. The conceptual framework was guided by House's (1981) work on social support, which posits major categories of support variables including emotional, informational, instrumental, and appraisal support. A nonprobability purposive sample consisted of 50 school-age siblings of children with cancer and their parents. Subjects completed either the parent or sibling version of the Nurse-Sibling Social Support Questionnaire (NSSSQ). Descriptive statistical analyses were performed to examine NSSSQ helpfulness and frequency scores for both siblings and parents. Paired t-tests were used to test the difference between the responses given by siblings and their parents on the NSSSQ helpfulness and frequency scales. Regression analyses were chosen to determine variables providing the most predictive power for helpfulness scores of well siblings. A Correlation Coefficient was calculated using the total score from the Personal Attribute Inventory for Children (PAIC) and the total NSSSQ scores for siblings to further explore the validity of the NSSSQ. Finally, using the NSSSQ, content analysis addressed the responses to the open-ended questions at the end of the instruments. Results demonstrated that siblings perceive interventions aimed at providing emotional and instrumental support the most helpful. Parents perceived interventions aimed at meeting the siblings' need for emotional and informational support the most beneficial. Simple regressions revealed no statistically significant results for any of the predictor variables.