The problem of finding new treatment methods fo r children with autism spectrum disorder (ASD) remains urgent. One of the ways to correct the manifestations of ASD is the Early Start Denver model (ESDM). This article describes a clinical case of a patient (a boy) with ASD. The child began an 8-month ESDM-based psycho-correctional intervention at the age of 4 years and 2 months. Each session lasted 50 minutes; they were held twice a week. One of the parents (the boy's mother) was an active participant in the sessions. Before and after the intervention, the child’s condition was assessed using the ADOS-2 and CARS scales, the E. E. Lyaxo speech development questionnaire, a measure of helping-behavior severity, and EEG. According to the supervising psychiatrist and his parents, the boy’s behavior has improved. Test results indicated a reduction in autism symptom severity (ADOS-2 score: 5 to 4; CARS score: 32 to 24), an increase in the percentage of correctly completed speech tasks from the Lyaxo questionnaire (46.5% to 54.0%), and increases in instrumental (2 to 10), emotional (0 to 5), and altruistic (0 to 9) helping behaviors, as well as in a combined altruistic–emotional helping behavior score (0 to 8). After the ESDM intervention, the child showed stronger µ-rhythm amplitude desynchronization on EEG during observation of another person’s actions. This clinical observation confirms that the ESDM technique can significantly impact the neural circuits underlying social behavior.