The purpose of this study was to examine the impact of both functional behavior assessment-based interventions and targeted classroom interventions for reducing problem behaviors of children with emotional/behavioral disorders (EBD) in special education classrooms. Specifically, this study was interested in how interventions based on changes in classroom routines and instructional behaviors compared with interventions based on functional behavior assessment. Results demonstrated the effectiveness of incorporating effective classroom practices in reducing problem behaviors in special education classrooms for students with EBD. In addition, results demonstrated a clear additive effect when individually designed behavior interventions, based on functional behavior assessments, were incorporated following classroom intervention. Results confirm the importance of analyzing and manipulating environmental and instructional classroom variables as an essential step in the process of addressing problem behavior. Implications for practice and future research are discussed. (Contains 2 tables and 4 figures.)