In this study our goal was to better understand the development of chemistry teachers who are involved in a continuous professional development (CPD) programme, focusing on using the inquiry approach in the chemistry classroom-laboratory, followed by protocols assembled in a portfolio that can be used to demonstrate evidence-based practice in chemistry teaching in the inquiry laboratory. Fourteen experienced chemistry teachers participated in a workshop, coordinated by three CPD providers from the Department of Science Teaching, at the Weizmann Institute of Science. The meetings, lasting about three hours, were conducted once a month. Of the fourteen teachers, some were videotaped while conducting inquiry-type experiments in their classes, and were interviewed immediately afterwards. Based on the findings, we conclude that the CPD programme contributed to the professional development of the teachers. The teachers became more reflective and more aware of their practice. In addition, we observed a change in their pedagogical knowledge and content knowledge regarding the inquiry teaching. Moreover, their anxiety concerning the implementation of the programme was reduced significantly throughout the year. (Contains 1 figure and 5 tables.)