Introduction and significance of the study: Chronic illness are defined as physical or mental conditions, that affect the daily functioning of individuals for intervals longer than three months a year, or for a duration of hospitalization longer than one month. Most of the children with chronic illness live at home, and their presence impacts family members even though the specific disabilities/chronic conditions may vary. A large number of households have a member with a disability needing care. These disabilities or chronic conditions/illnesses may affect the child's intellectual development (e.g., Down syndrome [DS] and developmental delay), emotional development (e.g., autism and bipolar disorder), or physical development (e.g., arthritis and other orthopedic conditions [OC]. Sibling relationships provide physical and emotional contact at critical life stages. These stages help children learn social skills. However, when a child suffers a chronic illness, sibling relationships may be altered strained because a chronically ill child is perceived as needing more protection and attention in order to survive. Aim of the study: The aim of this study was to assess caregiver perception of sibling relationships in families raising a child with chronic illness. Subjects and Methods: Research design: A descriptive exploratory design was utilized in this study. Setting: This study was conducted at the outpatient clinic of Zagazig University hospital and Altarbia Alfekeria School at Zagazig city. Study Subjects: The respondents were composed of caregivers of 108 families who have a child with chronic condition. Autism (n = 20, 18.5%); DS (n = 36, 33.3%); and Diabetes (n = 52, 48.2%). Data Collection Tools: One tool was used to collect the necessary data. It composed of two parts: Part (I): An interview questionnaire sheet. Part (II): Sibling Inventory Behavior (SIB): used to assess sibling relationships in families with a handicapped child. Results: The mean scores of empathy, avoidance, and teach/manage according to diagnosis had a high significant difference among Diabetes, Down Syndrome and Autism. Companionship according to diagnosis highly statistically significantly differed among diabetes, Down syndrome and autism. The strongest significant positive correlation was between empathy and teach/manage followed by the relationship between aggression/conflict and rivalry (r= 0.71 and 0.61) respectively at p <0.001. It can also be noted that Companionship has strong significant positive correlation between Empathy and Teach/Manage (r=0.55 and 0.54) respectively at p <0.001. While the strongest significant negative correlation was between avoidance and teach/manage, empathy and companionship (r= -0.48, -0.44, and -0.37) respectively at p <0.001. Conclusion: The current study showed some differences in perception of sibling relationships according to type of chronic condition. Caregivers rated sibling of children with diabetes as companionship, empathy and teach / manage than children with Down syndrome and autism. Also, caregiver perceived older siblings as having more companionship behavior than younger siblings while youngest siblings had avoidant behavior toward a child with a chronic condition than the oldest siblings. No statistically significant differences by sibling gender were found for caregiver perceptions of sibling relationships. Recommendation: Observational methods might be used in future research to assess sibling relationships because caregiver reports may underestimate or overestimate the kinds of interaction that sibling have with each other, and observational methods may capture a variety of relationships beyond those examined. Observational research could also enhance understanding by examining actual behavior between siblings as opposed to parental perception of sibling behavior.