Previous studies have found significant differences between the classroom behaviour of boys and girls. Most are within a single broad cultural context and little work has been done within an Arabic/Kuwaiti one. The main aim was to investigate the differences in behaviour between boys and girls in Kuwait primary schools. Data were collected that provided comparisons across questionnaires between parent and teacher returns for over 430 students. Separate teacher observations of students (n = 671) and classroom researcher observations were also obtained. Significant differences were found across the scales, indicating higher levels of externalising misbehaviour among boys than girls. A comparison with three studies conducted in other cultural contexts using the same strengths and difficulties instrument as used in this study found similarities and differences in results between the behaviour of boys and girls.