The purpose of this study was to examine the experiences of parents of children with autism during the transition from preschool to school within an Early Intensive Behavioural Intervention (EIBI) program. Qualitative interviews within grounded theory framework were conducted to gain a better understanding about parents’ perceptions of the social supports they received during the transition period. Data collection involved semi-structural interviews with six families whose children completed EIBI program at St.Amant and were enrolled in school. Due to the small sample size, a metasynthesis of five qualitative studies about the transition experiences of families with children with autism was added. This metasynthesis provided additional information to the data collected from interviews in order to strengthen the trustworthiness of the current study. All data collected from the interviews were coded, categorized and analysed using a constant comparative method. Findings from both data collection components emphasize the importance of parents’ involvement in the transition process and suggest that an effective partnership between the home, the EIBI program and the school is a significant factor to a successful transition. The findings also highlight the need for strategic planning of the transition process that is family-focused and involves an active role of a facilitator, who can offer practical guidance and support to children and their families. Practical implications and recommendations for future research are discussed.