There is a growing population of adolescent students with developmental disabilities (DD) in school settings. Educators are in need of evidence-based practices (EBP) to address the challenging behaviors of students with DD. A key consideration in determining whether practices should be considered as an EBP is whether these practices have been implemented with fidelity. Yet, previous research has shown that many studies fail to report treatment fidelity data, which may compromise the outcomes of studies examining interventions to reduce challenging behaviors for adolescents with DD. Reported fidelity is essential for having increased confidence that the study outcomes were in fact due to the intervention rather than some extraneous variable. Thus, the purposes of this review were to systematically evaluate the quality of research on challenging behavior interventions for adolescents with DD and examine the reporting of implementation fidelity in high-quality studies. Fifty-three studies were evaluated against the quality indicators developed by the Council for Exceptional Children. Recommendations for future research and implications for practice are discussed.