This study aimed to explore the prevalence of challenging behaviors (CBs) associated with students with severe developmental disabilities (SDDs) as rated by their teachers. The study also attempted to examine whether the occurrence and intensity of CBs might depend on certain socio-demographic variables. Data was collected using a questionnaire to rate the prevalence of CBs in 687 students with SDDs. Results indicate that social problems, stereotypical behaviors, and disobedient behaviors were estimated to be the most prevalent of CBs among such students. Positive correlations were confirmed between the type of disability, gender, age, school grade, educational placement, and the prevalence of CBs among students with SDDs. Implications for educational practice and recommendations for future research are discussed.