We examined to what extent elementary teachers' nature of science (NOS) and nature of scientific inquiry (NOSI) views, and science teaching efficacy beliefs change after a five-day professional development program designed to teach NOS and NOSI integrated with language arts. We found that elementary teachers improved their NOS and NOSI views, and one dimension of their science teaching efficacy beliefs at the end of the professional development program. Results of this study suggest that carefully designed professional development programs that provide NOS and NOSI instruction integrated with language arts may help elementary teachers improve their science teaching efficacy beliefs as well as their NOS and NOSI views.