Effective science education draws on many different ways of teaching science. The literature on science education documents some potential benefits of argumentation instruction as a powerful tool for learning science and maintaining wonder and curiosity in the classroom. Unlike expository teaching, which relies on a teacher-driven pedagogy in which students accept the teacher's authority over any content to be justified a priori, argumentation teaching allows students to focus on the importance of high-quality evidence for epistemic knowledge, reasoning, and justification. Using a quasi-experimental design, two study groups of undergraduate student teachers were exposed to two different learning conditions, the Exp-group with dialogic argumentation instruction (DAI) and the Ctrl-group with expository instruction. Each group received the same science content twice a week for 12 weeks (2 h per lesson). Pre- and posttests were administered to collect data. One-way MANCOVA with the pretest results as covariates showed that the instructional approaches (Wilk's [lambda] = 0.765, p < 0.001) had a significant effect on the tested variables after the intervention. A pairwise comparison of performance indices between the two study groups revealed that the exp-group was better able to evaluate alternative solutions and defend arguments for collaborative consensus on unstructured scientific problems. This suggests that dialogic argumentation instruction can be used to help students improve their scientific reasoning, thinking, and argumentation skills, which are required to solve problems involving scientific phenomena.