There have been numerous studies investigating the extent to which teacher-student classroom interactions differ between boys and girls and the results of these studies suggest that teacher negative feedback is higher for boys, which in turn leads to lower levels of on-task behaviour. The article describes the results of a quasi-experimental study, involving 30 teachers and a selection of 129 of their students, aimed at improving teacher feedback patterns, student behavioural responses and student perception of equity in the classroom environment. Fifteen teachers took part in a five-session professional development programme in which they investigated their own teaching practice by means of collaborative appreciative inquiry. The pre-test and post-test data in the control group illustrate that girls who receive very high levels of positive feedback at the beginning of the year succeed in maintaining and even strengthening their position as favoured students while at the same time lowering their level of raising hands and increasing their level of calling out to the teacher. By contrast, the data in the intervention group show a drop of very high levels of positive feedback and we see the levels of misbehaviour in boys and girls rise. Students' sense of equity increases for all conditions to some extent. The paper considers two alternative explanations for the results: some students actively resist changes in teacher treatment and various confounding factors might have been omitted. Implications and suggestions for further research and the design of professional development programmes on gendered classroom interactions are discussed.