The present study specifically focuses on science teachers' views about scientific inquiry and their use of scientific inquiry in their lesson plans, which were prepared at a professional development workshop designed for better utilization of science centers (SCs). As an impact evaluation research, qualitative data was collected from 41 purposively selected volunteer science teachers. The project team provided the participants with intense instruction in inquiry, and fostered them to learn nature of science and nature of scientific inquiry explicitly. The participants designed lesson plans that integrate school science curricula with exhibits at SCs before and after the workshop. An open-ended questionnaire about the views about scientific inquiry (VASI) was administered before and after the workshop, and teachers' post-lesson plans were analyzed to detect the presence of scientific inquiry aspects. The majority of teachers exhibited improved views about scientific inquiry based on the VASI instrument. Also, lesson plan analyses indicated that teachers, who showed more improvement in VASI, included more scientific inquiry (SI) elements in their post-lesson plans. It was observed that science teachers' lesson plans are limited in terms of teaching science in line with real scientific inquiries in SCs to make students learn about the nature of scientific inquiry while learning science. Only two groups embedded SI properly in the SC-oriented lesson plans, and teachers rather used inquiry-based methods of teaching (e.g., argumentation, predict-observe-explain) and process skills (e.g., questioning, explanations). Accordingly, further studies are suggested to develop a specific pedagogical content knowledge framework for teaching with/in SCs.