Purpose <p>This pilot randomized controlled trial examined the feasibility, acceptability, and preliminary effectiveness of a telehealth-based Pivotal Response Treatment (TPRT) program for preschool children with autism spectrum disorder (ASD) in Taiwan, where access to evidence-based, parent-mediated interventions remains limited in underserved communities.</p> Methods <p>Fifty children aged 24–72 months were randomly assigned to either the intervention group, which received a 12-week therapist-guided TPRT program, or the control group receiving general parent support. Parents in the TPRT group attended weekly online coaching sessions and practiced the strategies daily at home. After the 12-week intervention, all participants entered a 4-week follow-up phase, during which TPRT parents independently practiced and applied the learned strategies in daily routines without therapist supervision, allowing evaluation of their autonomous use and short-term maintenance of treatment effects. Post-intervention assessments at the end of the follow-up evaluated child developmental outcomes and parental stress.</p> Results <p>Compared with controls, the TPRT group showed significantly greater improvements in language and motor development, with medium-to-large effect sizes in adaptive functioning, particularly in daily living and motor domains. Parenting stress significantly decreased, with most parents reporting reduced distress and improved perceptions of child behavior. Program adherence was high (88% daily strategy use, 85% homework completion), and parental satisfaction averaged 93%.</p> Conclusions <p>The TPRT program was feasible, well accepted, and associated with meaningful developmental and parental benefits. Findings support the promise of telehealth-delivered, parent-mediated PRT as a scalable model to improve service accessibility for young children with ASD in underserved settings.</p>