Background <p>Autism Spectrum Disorder (ASD) is characterized by physical, communication, and behavioral challenges that often require comprehensive interventions. This study aimed to evaluate the combined efficacy of physiotherapy, occupational and speech therapies in improving physical and behavioral outcomes among children with ASD.</p> Materials and methods <p>This assessor-blinded randomized clinical trial was conducted at Proyash (Institute of Special Education), Jashore, Bangladesh, involving seventy children with ASD. Outcomes were assessed using the modified SF-36 for physical status and GARS-3 for behavioral status at baseline and after six weeks of intervention. Data were analyzed using SPSS version 25.0, with descriptive statistics (median and IQR) and inferential tests (Mann-Whitney U and Wilcoxon signed-rank), maintaining a 95% confidence level.</p> Results <p>The average age of participants was 10.66 ± 3.28 years in Group A and 9.17 ± 2.83 years in Group B. Group A had a higher BMI of 21.86 ± 7.96&#xa0;kg/m² compared to 19.53 ± 4.85&#xa0;kg/m² in Group B. Post-intervention analysis revealed significant improvements in both physical and behavioral outcomes. Between-group comparisons yielded p-values &lt; 0.01 for both measures. Within-group analysis showed significant improvements in Group A (<i>p</i> &lt; 0.01), whereas changes in Group B were not statistically significant.</p> Conclusion <p>The combined rehabilitation program demonstrated significant improvements in physical and behavioral outcomes and showing greater effectiveness overall. These findings emphasize the importance of customized rehabilitation approaches in enhancing both physical and behavioral health, particularly when tailored to specific participant profiles.</p> Trial registration <p>CTRI/2024/07/070209 (Prospectively Registered).</p>