In the context of educational innovation, it is important to examine how in-service teachers learn and adapt their knowledge to changing professional circumstances. The authors examined the informal learning of a small number of experienced science teachers in their first few years of teaching a new science syllabus in secondary education in the Netherlands.The storyline method was used to elicit the teachers’ perceptions of their learning from experiences at work. Implications for professional development initiatives are discussed, as are suggestions for initial teacher education.