Addressing the challenging behavior of a preschooler is a tough job for parents and teachers. Thus, this case study aims to come up with a model that could be used by the Center for Career, Counseling, and Student Welfare to help lessen the challenging behavior of any preschooler in the university. The researcher tried to examine the behavior of a preschooler who has been reported by her parent and teacher to have a challenging behavior inside the classroom. A functional assessment interview was conducted in order to get a multiple baseline of facts. Likewise, a 10-s continuous partial interval system recording was used. Finally, to make sure that the case study is wholistic, a psychodiagnostic assessment was employed to look for the mental status and personality dynamics of the preschooler. Based on the assessments done, a positive behavior support plan had been drawn: (1) practicing consistent discipline (2) offering choices on activities and materials, (3) using visual cues or modeling to teach the preschooler to engage in a structured activity, (4) observing constant routine at home and at school to minimize restlessness, (5) providing tutorial sessions that focus on developing basic skills, and (6) consulting a psychologist/therapist to deal with some behavioral and psychological concerns. Implementing the proposed model with the same subject is highly recommended to find out if it is an effective intervention for a child with a challenging behavior.