Introduction: Many teachers lack the skills to effectively deal with behavorial issues when they arise and may not be familiar with behavorial techniques to utilize with students who have behavorial disabilities. The aim of the present study is to understand the extent to which pre-service teachers adequately understand functions of behavior and behavorial principles related to classroom behavior management. Method: Participants included pre-service students who were currently enrolled in an under-graduate university-based educational licensure program. The researcher videotaped three short 4-minute vignettes that displayed adult actors portraying a variety of behaviors. A questionnaire was formulated and given to the participants of the research study that asked then to determine the type of reinforcement begin displayed in the vignette a well as to determine the specific function of the behavior in a multiple choice format. Additional background information was gathered from each participant. Results: Results indicate that pre-service teachers vary in their ability to correctly identify behavior function after viewing video demonstrations of behaviors and that they were even less successful in correctly labeling behavior scenarios as being as being demonstrations of positive reinforcement, negative reinforcement, or punishment. No variables were identified that predicted participants' accuracy in determining behavior function. Discussion and Conclusion: These findings support that notion that many pre-service teachers lack a sufficient level of knowledge of behavior function in order to accurately identify the nature of the problem and provide differentiated behavior supports.