Handheld computer technologies and probeware have the potential to support inquiry-based science projects in K-12 education. Teacher training is important for effective integration of inquiry-based learning to provide students with rich and authentic learning experiences. This article describes the implementation and results of a project designed to train teachers to use an inquiry-based approach to science education with the help of emerging handheld technologies. The project included training of elementary and middle school teachers on methods of inquiry-based science, integrating handhelds and probes, and development of inquiry-based science lessons. It was intended that the teacher participants model development and implementation of inquiry-based science lessons using handheld computer technologies.