Families of autistic youth often support their children's transition from adolescence to adulthood. During this time, families learn to navigate the complex shift from school-based to adult disability services. For Latinx (vs non-Latinx White) families of autistic youth, transition is especially difficult because of the systemic barriers (e.g. language) Latinx families face when accessing services. Unfortunately, few interventions aim to improve the transition among Latinx families of autistic transition-aged youth. This study examines the effectiveness, feasibility, and acceptability of the ASISTIR (Apoyando a nueStros hIjo/as con autiSmo obTener servIcios de tRansición; Supporting our Children with Autism to Obtain Transition Services) program, a six-session program for Latinx families of autistic youth, with respect to increasing: school-based transition planning and adult disability services knowledge, empowerment, and advocacy. Twenty-nine participants were included in this single-group, intervention study. After completing the program, participants demonstrated significantly improved: knowledge of school-based transition planning and adult disability services, advocacy, and empowerment. In addition, participants were highly satisfied with the program, based on the formative and summative evaluations and individual interviews. Implications for research and practice are discussed.