Conservation of chemical identity, composition, and mass are essential to the basic understanding of chemistry. In an investigation carried out with 11 to 12 year old children, using techniques analogous to those of Piaget, it is shown that, even after the completion of an introductory course in chemistry over a nine month period, conservation had not been attained in a considerable proportion of subjects. The frequencies of non-conservation responses were in the order composition > identity > mass. It is concluded that re-examination of introductory courses with a view to facilitating attainment of conservation may be called for.