Argumentation is an indispensable part of scientific knowledge construction, and the inquiry laboratory is full of opportunities for argumentation. Yet, at primary schools, students learn science without any inducement to argumentation or inquiry. To fill this need, this study was aimed to develop pre-service primary teachers' understanding of and skills in relation to scientific argumentation. In the study, we applied the principles of argument-driven inquiry (ADI) laboratory in the Science and Technology Laboratory Applications course. The participants were 57 pre-service primary teachers (PPTs). The research design was an embedded mixed method design, in which qualitative data was embedded in the quantitative design. The quantitative design was pre-test, post-test one group experimental design. The main sources of data were the Argumentation Test (AT) and PPTs' written arguments. The PPTs actively participated in 5 ADI laboratory works after they were introduced to inquiry and argumentation in 4 preparatory laboratory sessions. The results showed statistically significant development of PPTs' understanding of argumentation based on the analysis of AT responses. The analysis of written arguments supported these results by indicating improvement in PPTs' arguments from weak to strong arguments. Implications of these findings highlight first, the efficacy of ADI laboratory work in engaging pre-service primary teachers in argument and inquiry-based instructional practices, and second, in supporting understanding of and skills regarding argumentation given the significance of their role in promoting scientific literacy.