According to the systems perspective, the influence of various systems (e.g., family, school, community) on children's behavior at school is highly acknowledged. It is therefore accepted that problem behavior in the classroom originates from social interactions, providing a conceptual framework where problems are seen as indicative of dysfunction within the school system, thus removing blame from the individual child, the teacher, or the parents. Addressing the importance of interactions among students, teachers, and parents in this system, the present study aimed to identify and compare the types of behaviors that Greek primary and secondary teachers and parents view as problematic in the classroom. A sample of 378 teachers and 69 parents were asked to identify which behaviors were considered troublesome. Exploratory factor analysis revealed five categories of behaviors perceived as problematic by parents and teachers: Externalizing behaviors, School Difficulties, Internalizing behaviors, Attention seeking behaviors, and Hyperactivity/attention difficulties. Both teachers and parents considered externalizing behaviors to be more troublesome than other types of behavior. Teachers tend to worry less than parents about all types of children's behaviors, except for school difficulties. The findings highlight the importance of considering diverse perspectives within the school system when designing interventions to address the specific needs of school communities while also promoting collaboration among all members of the school system.