Millions of Americans use the Internet as a resource for information, with a large proportion seeking health information. Research indicates that medical professionals do not author an extensive amount of health information available on the Internet. This creates a possibility for false information, thereby potentially leading ill people away from proper care. One way to begin addressing this problem is to assess perceptions of credibility about information found online. A between-groups, 2 (message type) × 3 (source type) factorial design was tested by manipulating source expertise (high, medium, low) and content knowledge (known and unknown). While findings did not indicate a significant interaction between source and content type, they did indicate an overall tendency to rate all information as relatively credible. In addition, results indicate that both knowledge of content and source expertise affect perceptions of online health information.