Along with the COVID-19 outbreak, which has been a global threat for public health, the unconfirmed information about the pandemic in circulation has become another threat. Hence, it has become important to improve public understanding of science with a focus on explaining the nature of uncertainty in science and its impacts. The goal of the present study was to explore pre-service teachers’ analysis of claims related to the COVID-19 pandemic throughout an 8-week online implementation of a pre-service teachers’ analysis task, focus group interviews, and instructor’s feedback to this analysis in a course focusing on critical and analytical thinking. In order to achieve this purpose, the researchers used the claims that contain fallacies, conspiracy theories, and scientific arguments related to the COVID-19 pandemic as an assessment tool. The researchers developed and used a rubric consisting of the high, moderate, and low levels of analysis in three different categories including evaluation of claims, demarcation of fallacies and conspiracy theories from scientific arguments, and judgment of the credibility of sources. The findings indicate that the participants analyzed the claims rarely at a high level before the focus group interviews. However, after the focus group interviews, almost every participant’s analysis scores of evaluation, demarcation, and judgment increased. The results also revealed their commitment to various fallacies and conspiracy theories while arguing the claims. Concluding remarks are made for the further implications of teaching critical evaluation of claims based on evidence.