Scientific literature has shown abundantly that teacher professional development is a crucial factor for improving the quality of education. In this frame, this research analyzes teacher professional development of in-service higher education teachers who participated in training activities. This research has five goals not previously studied simultaneously in teachers' professional development, namely: (A) improve teachers' conceptions and beliefs; (B) improve argumentative teaching practices; (C) analyze teachers' reflections; (D) establish the hypothetical relationships between types of knowledge of objectives (A), (B), and (C); and (E) analyze knowledge decay after 7 years. The research can be considered as a case study developed in-depth using multiple techniques for data collection and triangulation. The findings strongly evidence a relationship between conceptions and beliefs, argumentative teaching practices, and reflections. In addition, three stages are characterized for teacher professional development, as well as the relationships between the types of knowledge for each stage.