Core symptoms of Autism Spectrum Disorder (ASD) impact the child's abilities to interact with others, especially with the primary caregivers. Most research has focused on investigating the mother-child dyad, but the paternal role in interaction with children with ASD is mainly unexplored (e.g., Rankin, Paisley, Tomeny & Eldred, 2019; Flippin & Crais, 2011). For this, the project's first aim is to examine paternal interactive characteristics and behaviors and compare father-child and mother-child interactions with children with ASD, delineating the strengths and weaknesses of both caregivers in a complementary system. Based on this investigation, we implemented a personalized and parent-specific early intensive intervention that may guarantee better developmental trajectories for children with ASD. Consequently, the project's second aim is to assess the impact of intervention with parental involvement through cognitive, socio-communicative, and dyadic behavioral measures using a longitudinal study with pre- and post-assessments. At this point, it is fundamental to evaluate how several traits of children and caregivers might impact the treatment response. To reach this aim, while assessing developmental trajectories, we wanted to identify a-priori individual differences at both child and caregiver’s level and dyad dynamics that may influence intervention outcomes. We identified markers of better developmental trajectories and discussed implications for clinical practice in providing practitioners with more information about areas to be targeted during the intervention.