Teachers involved in the implementation of a curriculum innovation can be prepared for this task through a professional development program. In this paper, we describe essential characteristics (identified empirically and theoretically) for such a professional development program that promotes the acquisition of competences by these teachers. The innovation deals with the introduction of modules from a new multidisciplinary subject, in which elements from physics, chemistry, biology, mathematics, and physical geography are integrated. A 3-step approach was used to identify the essential characteristics: (a) evidence from classroom practice, (b) characteristics of the new subject, and (c) theoretical and empirical evidence from curriculum implementation studies. Analysis of the data showed that 5 characteristics need particular attention in a professional development program.