Naturalistic, Developmental, and Behavioral Interventions (NDBIs) are an empirically supported intervention approach for young autistic children and their families. Spanish-speaking (SS) Latinx families have been underrepresented in autism intervention research, limiting our understanding of whether NDBIs are aligned with Latinx family values and belief systems. This study piloted a parent-mediated NDBI, Project ImPACT, within outpatient services for SS Latinx families. We aimed to examine the preliminary impact of Project ImPACT on family and child outcomes while using the Ecological Validity Model to evaluate program adaptations made by bilingual clinicians. Results from 15 families indicated good treatment completion and high satisfaction, alongside significant increases in child social communication skills and parent self-efficacy in supporting their child's development. Mixed-methods data examining program adaptations indicated the need to provide additional information related to autism, bilingual language development, and service navigation, as well as adaptations to language and metaphors used in the program.