There is currently a lack of research into classroom climate as perceived by the students themselves. This article presents a new classroom climate evaluation instrument which is designed to gauge student perceptions of their own level of engagement in academic activities, their relationships with peers, and the level of support they feel from their teachers. The Classroom Climate Index was pilot tested with a group of 105 elementary students aged 8-12. The pilot data were factor analysed, and the instrument was refined accordingly. Following the pilot test, the refined instrument was next administered to a larger sample of 2340 elementary students. Data from the comprehensive study were subjected to factor and reliability analyses, the results of which support the use of the Classroom Climate Index in measuring student engagement, supportive teacher behaviour, and collegial support from the student perspective.