Background: All guidelines for the treatment of ADHD in children include behavioral parent training in combination with other strategies. In the past, several systematic reviews have been carried out that were either outdated or not sufficiently specific to ADHD. We wanted to conduct a new review focusing on a specific ADHD population of school age (4–12 years) and on behavioral and cognitive programs. We aimed to test our hypothesis that behavioral parent training would improve parents’ difficulties, children’s symptomatology, and the quality of life of families with ADHD. Methods: PUBMED, PsychInfo, Web of Science, ERIC, and Cochrane databases were searched for original articles on randomized control trials on behavioral parent training group for children with ADHD aged from 4 to 12 years until July 2023. Results: A total of 20 studies were included in the systematic review. The results were divided into four categories: parent data, child data collected by parents, teachers, or researchers. A qualitative analysis revealed for parents, effects on parental stress, feelings of parental efficacy, and negative parental educational behavior. As regard children, only effects are noted for parental assessment, on ADHD symptomatology, externalized disorders, and social skills. Conclusion: Despite the heterogeneity or small number of studies in some categories, BPTs have positive effects on both parents and children. There are no convincing results to support the generalization of progress. This would seem to indicate that it remains essential to consider actions specific to each problematic environment for the child.