Teachers are viewed as the most significant factor affecting student learning. However, research in science education showed that teachers often demonstrate misunderstandings of science very similar to students. The purpose of this research was to correct conceptual difficulties in science of Thai primary school science and non-science teachers using inductive learning activities in a teacher training program. An eighteen hour teacher training program was designed to address conceptual difficulties in science based on research findings of three science concepts including force and motion, simple electric DC circuits, and astronomy. A pre- and post-test with 15 multiple-choice questions for each of those concepts were administered to thirty volunteer primary school science and non-science teachers in 2014. Data was entered into Excel and analyzed for a correct percentage for each question. There were overall gains in understanding between the pre- and post-tests for these three concepts when teachers were taught by inductive methods. It suggests that using inductive learning activities can be used as a meaningful teacher training program for science and non-science teachers to correct conceptual difficulties in science.