Given the need to educate future critical thinkers, it is necessary to explore preschool teachers' level of argumentation about socioscientific issues in order to facilitate their use of appropriate strategies for effective argumentation in their own classrooms. To achieve this aim, it is also necessary to propose the use of a set of previously developed evaluation criteria to assess a wider range of skills and enable preschool teachers to use socioscientific issues (SSI) scenarios effectively. Therefore, the qualitative research study presented here examined 19 preschool teachers' analysis of two SSI scenarios by using a set of previously developed evaluation criteria, namely the structure of observed learning outcomes (SOLO). One of the scenarios consisted of a discussion between two people presenting opposing arguments about vaccines and the other scenario involved a dialog between a mother and her child discussing the position of humans on the Earth. The findings revealed that the preschool teachers were challenged to critically analyze arguments in each scenario and despite the variety of questions that they asked; they rarely asked questions to facilitate inquiry or refute circular reasoning. The implications of this study suggest employing argumentation by using scenarios and designing critical thinking activities in early childhood teacher education programs. The results also suggest further investigations of preschool teachers' activity designs regarding their ability to facilitate critical thinking.