This study sought to examine whether teachers' and educational administrators' conceptions of inquiry promote or constrain inquiry-based science teaching in junior high schools. The study also explored any connections between participants' conceptions of scientific inquiry, inquiry teaching, and inquiry learning. Multiple-case study involving semi-structured interviews was used to collect data from 18 integrated science teachers and 23 educational administrators from rural and urban areas in the Central Region of Ghana. Analysis of the qualitative data involved open coding and categorisation of participants' responses. We found that all the teachers and educational administrators held either uninformed or partially informed conceptions of scientific inquiry and inquiry teaching and learning which, constrain inquiry-based science instruction in junior high schools. We also found that participants' conceptions of scientific inquiry reflected in their conceptions of science teaching and learning. Again, we found that the uninformed conceptions of inquiry developed from participants' lack of exposure and experiences with inquiry-based science instruction when they were students. We recommend regular explicit-reflective in-service trainings to promote teachers' and educational administrators' conceptions and teachers' practice of inquiry-based science teaching. We also recommend reforms in preservice science education that emphasise the engagement of prospective teachers in collaborative explicit-reflective inquiry investigations and instructional practices.