This study investigates the relationship, if any, between teacher participation in a targeted professional development programme and changes in participants' instructional practice and their pupils' attitudes to learning primary science. The programme took place over a 2-year period in 15 small rural schools in the West of Ireland. Data sources include teacher and pupil questionnaires, semi-structured interviews and informal classroom observations. The findings reveal that as a result of their involvement in the programme, (a) teachers' instructional practice in science lessons became more inquiry-based and they were engaging their pupils in substantially more hands-on activities in science lessons and (b) pupils developed more positive attitudes towards learning science. The findings from this study add to what is known about delivering effective professional development.