Background <p>This qualitative study explored the social isolation experiences reported by mothers of autistic children in Yazd, Iran.</p> Methods <p>Twenty-two mothers of autistic children aged 4–12 years participated in semi-structured interviews conducted in Yazd, Iran. Data were analyzed inductively using conventional content analysis. The reporting of the study was strengthened using the COREQ checklist, including additional details on the interviewer, recruitment, interview procedures, coding, trustworthiness, and consistency between the thematic table and the Results section.</p> Results <p>One main theme, social isolation, was developed from participants’ accounts. Three categories were identified: stigma and social judgment, inadequate formal and informal support, and caregiving burden and defensive withdrawal. The twelve subcategories reported in the thematic table are now aligned with the Results section. Participants’ accounts suggested that social isolation was linked mainly to stigmatizing social responses, community misunderstanding, limited family and service support, therapy-related demands, and mothers’ protective withdrawal from social settings.</p> Conclusions <p>In this sample of 22 mothers in Yazd, social isolation appeared to be shaped by the interaction between autism-related caregiving demands and the surrounding social and cultural environment. The findings support the need for culturally sensitive public awareness, family education, and accessible support services. Because this was a single-city qualitative study based on mothers’ self-reported experiences, the findings should be transferred cautiously to other Iranian or international contexts.</p>