This phenomenological study investigated co-teachers' perceptions of their collaborative relationship with their teaching partners and is limited to relationship collaboration factors. The researcher did not ask about other practical matters, such as preparation time, administrative support, resources, class size, or other related issues. Typically, school administrators assign co-teachers in co-teaching teams and the co-teachers are not paired for effective collaboration. When co-teaching teams work successfully in a collaborative relationship, this collaboration can impact student learning. Therefore, pairing co-teachers' collaboration factors is essential for maximizing teamwork for improving student performance in the inclusive classroom setting. The results of the research study may assist school administrators and co-teachers in identifying relationship collaboration factors. The study may be used for pre-service teacher collaboration coursework and professional development in co-teaching relationship collaboration.;The research study was conducted at two suburban school districts in the northeastern region of the United States. The first school district has a high proportion of students from low-income families and students with special needs. The second school district consists mostly of middle-income families with fewer students identified as having special needs. Co-teacher relationship collaboration factors and the perceptions of the co-teachers' collaborative co-teaching relationship were investigated through the use of ten qualitative open-ended interview questions. The audio digital recorded interview questions investigated the relationship collaboration factors of respect, communication, parity, and trust in the co-teaching relationship and the co-teachers' perceptions of the collaborative co-teaching relationship.;Results of the study indicated that the co-teachers expressed concerns in the following relationship collaboration factors: respect, communication, parity, trust, and conflicting co-teacher personalities. Communication, parity, and conflicting co-teacher personalities were expressed as primary concerns and respect and trust issues were lesser concerns. The co-teachers named effective communication as the most important factor and trust was identified as the least important factor in the co-teaching relationship. For co-teaching collaboration, interdependence was addressed as essential for effective teamwork. Limited time for co-teachers to plan and prepare for instructional needs and conflicting co-teacher personalities were identified as major concerns throughout the co-teacher interviews. A fifth relationship collaboration factor that emerged from this research study was conflicting co-teacher personalities. Finally, the co-teachers perceived their collaborative relationship with their teaching partners by the five identified relationship factors. |