Elementary public schools remain the most common venues for addressing children's severe conduct problems. Nevertheless, very few longitudinal studies have examined association between receiving psychoeducational services for conduct problems in school and subsequent conduct problem severity. This study explored if psychoeducational service reception contributed to reduce conduct problems in a sample of 434 elementary school-aged boys and girls presenting a high level of conduct problems. The study used a repeated measures design at 12-month intervals, for 4 years. Information regarding the severity of children's conduct problems and services was provided by parents and teachers. Latent Growth Modeling was used to identify a mean trajectory of conduct problems. Results revealed that psychoeducational services were associated with a decrease in conduct problems over time, but this association was only observed in boys. There was no association between service reception at study inception and the trajectory of conduct problems among girls. These results suggests that psychoeducational services are well suited to the difficulties of boys with conduct problems; however, they may call for a review of the services offered to girls in schools, both in terms of the detection of conduct problems in young girls, and in terms of their treatment options.