BACKGROUND: Siblings adjust to having a brother or sister with a disability in diverse ways. This study investigated a range of child, parent and family factors as predictors of sibling adjustment outcomes. METHODS: Forty-nine siblings (aged 7-16 years) and parents provided information about (1) sibling daily hassles and uplifts; (2) sibling coping; (3) parent stress; (4) parenting; and (5) family resilience. Multiple regression techniques were used. RESULTS: It was found that parent and family factors were stronger predictors of sibling adjustment difficulties than siblings' own experiences of stress and coping. Specifically, socio-economic status, past attendance at a sibling support group, parent stress, family time and routines, family problem-solving and communication, and family hardiness-predicted sibling adjustment difficulties. Finally, siblings' perceived intensity of daily uplifts significantly predicted sibling prosocial behaviour. CONCLUSIONS: The results revealed that the family level of risk and resilience factors were better predictors of sibling adjustment than siblings' own experiences of stress and coping resources, highlighting the importance of familial and parental contributions to the sibling adjustment process. The implications of these results for the design of interventions and supports for siblings are discussed.