Previous research conducted on siblings of children and adults with Autism Spectrum Disorder (ASD) has yielded inconsistent results regarding their psychosocial development. Previous research results suggest higher levels of loneliness and shame in social situations, but also moderate to high levels of empathy in this population. The purpose of this study, conducted as part of an undergraduate dissertation, was to gain a deeper understanding of the social relationships of individuals who grew up with a sibling with ASD in the Republic of Croatia. A purposive sample of eight typically developing adults aged 20 to 25, who have a sibling with ASD, participated in semi-structured indepth interviews. The eligibility criteria for study participation included a diagnosis of a higher degree of impairment in the sibling with autism spectrum disorder, specifically 3rd (N=2) or 4th degree (N=6) of impairment according to the findings of the expert body. Thematic data analysis was conducted for the purposes of this research. Regarding social relationships, the themes emerging from the thematic analysis include the following: Desire for social interaction, Communication with friends, Friends as a source of support, Support from extended family and relatives, and Unpleasant social experiences. Siblings of individuals with ASD frequently emphasized the importance of emotional support from friends. Additionally, they highlighted the significance of emotional, financial, and instrumental support from their extended family and relatives. They described various experiences related to feelings of loneliness, ranging from the absence of such experiences to their prevalence. Participants also had varying experiences with peers, ranging from peer support to instances where participants experienced misunderstanding or even bullying.