An elementary version of the "Questionnaire on Teacher Interaction" (QTI) and a scale for determining students' "Enjoyment of their Science Lessons" (ENJ) were translated into Standard Malay. This process, together with its initial validation carried out in 136 classrooms with 3,104 students, is described in this paper. Statistical analyses revealed that data from this Malay version of the QTI with these Malay-speaking elementary school students in Brunei are indeed valid and reliable. Associations between students' perceptions of their teachers' interpersonal behaviours and their end-of-year results on an external science examination were investigated. Students' perceptions of cooperative behaviours were positively correlated, while submissive behaviours were negatively correlated with their cognitive achievement. Cross-national comparisons were made between students' perceptions of teachers' classroom interaction and similar studies in Singapore, Australia, and Korea.