This study assessed the expressive language development of M.T, a 5-6-year-old child with Autism Spectrum Disorder (ASD), following a STEAM educational intervention conducted in April 2023. Using a structured plan aimed at enhancing expressive language, the project involved activities like “Making Scented Jars” and “Making a Bird's Nest.” M. showed marked improvements, scoring 36 points in the post-intervention assessment, a 10-point increase from the baseline, placing him in the "Fair" category (Level 3). Key progress areas included the ability to present using visual aids and answer open-ended "Why?" questions. Initially unable to present and displaying negative reactions, M. gradually understood presentation structures and organized content more logically. He began to use simple negative sentences and sequence words effectively in storytelling. Additional gains were observed in daily use of names, actions, qualities, and polite expressions, indicating broader communicative improvement. Feedback from teachers and parents highlighted increased attention, interest, and confidence in STEAM activities. M.'s ability to engage in storytelling and role-playing significantly enhanced his classroom participation and reduced the need for external support. These findings underscore the potential of tailored STEAM activities to foster language development in children with ASD.