Around the world, there have been curricula reforms involving the incorporation of the inquiry-based teaching and learning strategy in secondary school science education in general and in practical work in particular. Research in inquiry-based practical work (IBPW) has focused, for example, on aspects of the strategy itself, on teacher professional development, and on classroom teaching and learning based on the strategy. However, the question of the extent to which teaching practices linked to the implementation of practical work are actually inquiry-based, was still to be answered. To draw on the answer to this question to inform professional development practice and research, we focused on the case of physical sciences classrooms in two resource-constrained South African schools. In this regard, we used a conceptual framework based on the Interconnected Model of Teachers' Professional Growth and including a framework of teaching practices. In the data collection, we used a multimethod case study approach and to analyze the data, we combined the inductive and deductive approaches in thematic analysis. The results show that in the initiation, planning, and classroom implementation phases of practical work, many of the teaching practices of participants were inconsistent with inquiry-based teaching and learning, although some other practices were consistent with this type of teaching and learning. At the same time, some of the consistent practices were at a rather low level of implementation. We have discussed the theory-, practice-, and research-based implications of these results, in relation to the implementation of IBPW in resource-constrained physical sciences classrooms in South Africa and internationally.