This project examined one teacher's perception of the usefulness of the Reintegration Readiness Scale (RRS) to assess and monitor the social and emotional competence of a Year 1 student in a New Zealand primary school. The teacher participant was a highly experienced New Entrant teacher. She was initially interviewed about her perceptions of the possible outcomes for a Year 1 male student exhibiting challenging behaviour and this interview was followed by an assessment of the student's social and emotional competence using the Reintegration Readiness Scale. The information from the RRS assessment was then used to develop an Individual Behaviour Plan (IBP) for the student. Following an eight week intervention, a second RRS and a second interview were conducted. Despite a decrease in scores in the second RRS, results from the interviews indicated that the teacher perceived the Reintegration Readiness Scale as helpful in increasing her understanding of the student and his behaviour, which in tum, led to improved communication with the student's parents. The teacher reported the RRS as an easy-to-use framework from which to develop an Individual Behaviour Plan for the target student. The teacher noted that the focus on the student's social and emotional competency 'refreshed' her own professional development around managing challenging behaviour. She also found the information the RRS provided useful for planning and implementing a class-wide social skills unit on sharing and tum taking. Future research is necessary to ascertain if other teachers find the RRS a useful assessment and monitoring tool when working with students with challenging behaviour in mainstream New Zealand classrooms.