<p>The present study examined the effects of a culturally adapted intervention, <i>¡Iniciando!</i> la Adultez, on sleep and health-related quality of life (HRQoL) in Latino young adults with autism spectrum disorder (ASD) and their Spanish-speaking parents. The intervention targeted the transition to adulthood, a period associated with increased challenges in sleep and HRQoL, particularly for underserved Latino populations. Participants included 26 young adults and 38 parents who completed assessments at baseline and post-treatment. The results indicated significant improvements in several HRQoL domains for both groups, with young adults reporting enhanced emotional well-being, social functioning, and general health. Parents experienced notable improvements in subjective sleep quality, sleep latency, and global sleep quality, alongside enhanced emotional well-being and general health. Correlational analyses revealed significant associations between baseline sleep quality and post-treatment HRQoL, acculturative stress, and mental health outcomes, suggesting the interconnectedness of these factors. Parents generally reported poorer sleep and HRQoL than young adults at both time points, highlighting the ongoing challenges they face. Despite some improvements, overall sleep quality remained suboptimal, emphasizing the need for further refinement of interventions. This study underscores the importance of culturally tailored approaches in addressing the unique needs of Latino families affected by ASD and highlights the potential benefits of such interventions in improving sleep and HRQoL. Future research should explore the long-term sustainability of these improvements and address the remaining gaps in sleep quality. The findings contribute to a growing body of evidence supporting the need for culturally sensitive interventions in promoting well-being in marginalized communities.</p>