Working on What Works (WOWW) is a manualized, 10‐week classroom intervention based on solution‐focused brief therapy. This study evaluates WOWW using a randomized experimental, posttest‐only design. The study included 30 fourth and fifth grade classrooms, containing 30 teachers and 413 students. Results indicate no significant differences between WOWW and control groups for student internalizing and externalizing behaviors, student‒teacher relationships, student academic performance, or teacher sense of efficacy. However, students in the WOWW group had significantly fewer days absent from school compared with the control group. Additionally, teachers’ ratings on WOWW classrooms’ performance improved significantly more than teachers’ ratings on the control classrooms. Results from this study show that WOWW is a feasible intervention for therapists to use in schools and can be implemented across classrooms in both public and private schools. WOWW has potential to improve student attendance and classroom performance, both of which are important areas of concern for schools.