The purpose of this research was to examine the effects of a co-curricular program on the behavior of seriously emotionally disturbed (SED) middle school students. Co-curricular activities are any school-based activities that give students an opportunity to blend the various aspects of their academic learning with personal actions. This was an action research study conducted in a middle school special education program. The participants were 10 middle school students identified as seriously emotionally disturbed. These students participated in the planning and evaluation of their involvement in co-curricular activities during this year long study. Participant observations, interviews, student and staff journals, and documentary evidence provided data for the development of case records. The study generated the following results: Participation in co-curricular activities increased the sense of belonging for these students at this middle school. Seriously emotionally disturbed students reported that adult mentors significantly influenced their level of success. Seriously emotionally disturbed students had higher grade point averages and better attendance and fewer disciplinary issues during this study. During co-curricular activities, these students demonstrated leadership, thinking, communication, and cooperative learning skills that were not apparent in the regular classroom settings. Seriously emotionally disturbed students responded favorably to a solution-focused model of education. Parents reported that their students engaged in more leisure activities involving peers outside school, and were easier to live with at home. Students identified the privilege of participating in co-curricular activities as motivating them to minimize their past use of counter-productive social strategies during interactions with peers and adults. Latino students found it difficult to participate in activities with Anglos if other Latinos did not view the activity as acceptable. The primary implication of this research for schools is that co-curricular programs appeared to increase the sense of belonging for middle school SED students which influenced more positive social and academic behaviors. / Graduation date: 1999