The prevalence of unverified information on the internet and the associated potential adverse effect on society led to the development of a number of models and theories to assess the credibility of online information. Existing research consists of two diverse approaches: the first consists of checklist approaches or normative guidelines on how to assess the information whereas the second provides descriptive models and theories of how users actually go about when assessing credibility. The above mentioned approaches consider aspects related to the presentation and content of the information. However, the reasoning in the content is not a concern that is covered in these approaches. Critical thinking is considered an increasingly important 21st century work place skill. This paper investigates the potential value of using critical thinking in assessing the credibility of online information. The paper commences with an overview of existing approaches for assessing the credibility of online information. It then argues that the presence of a well-developed argument in online information to be an indication of credibility. Critical thinking also helps to evaluate the credibility of evidence. These thinking skills can be developed through training. It is shown how a group of first year Information Systems students were able to more critically engage with the content of online news after a course on critical thinking. This paper contributes to the literature on the assessment of the credibility of online information.