Background: Giving up prescriptive views on the teacher’s action in the classroom is necessary for a better understanding of the teaching work. We are also faced with the absence of works that address teaching action under an investigative bias in initial teacher education. Objectives: identify and categorise the actions intended and performed by preservice teachers in a chemistry class, looking for implications for teacher education. Design: the study fits into a qualitative-interpretative research perspective. Setting and Participants: The data analysed comes from the monitoring of chemistry teaching degree students in the Supervised Teaching Practice discipline and their teaching in a 9th-grade class in a public school. Data collection and analysis: data collection took place through different instruments: lesson plans and audio and video recordings of the classes, that enabled interpretations based on the assumptions of the textual discursive analysis. Results: for the actions intended, a small set of five actions was identified (question, write, explain, organise, identify). The actions carried out, on the other hand, include a larger set of 13 actions and, mainly, microactions, made possible by the actions intended. There is a convergence between the actions initially planned and development in the departments, and the emergence of specific actions in the context of the Supervised Practice. Conclusions: Such results indicate the importance of categorising the actions of the undergraduate students in a chemistry class, resulting in a set of actions not yet identified in other studies, and discussing the importance of the Teaching Practice in the constitution of elements of the teaching work.