This article reports on 18 months of action research that monitored British pupils' learning about the nature of science, using some aspects of history of science for the purpose. The action research took place within five classrooms and involved practicing teachers who used a set of historical materials specially written for this study. Preliminary findings about the common perceptions of the nature of science held by middle school pupils (age 11–14 years) guided the work, which was carried out using a variety of methodologies. The results obtained show some areas of substantial progress in the pupils' understanding of the nature of science, and others where little change seems to have been effected.