The current work was conducted to better understand the influences of source presence and individual differences on evaluating and sharing information from multiple conflicting Internet texts about childhood vaccinations. The results indicate that college student readers appeared to be insensitive to a source availability manipulation. However, their preexisting beliefs, specifically in terms of their misconceptions regarding childhood vaccinations, appeared to be detrimental to their online information sharing proclivities. In particular, readers with misconceptions about childhood vaccinations were more likely to include inaccurate concepts when writing an essay to share with a friend. Additionally, readers with misconceptions were less able to distinguish more from less credible information, in terms of reliability. The patterns suggest that readers with misconception-based beliefs may be at risk for misinforming others after reading multiple conflicting texts on the Internet. Limitations and future directions of the current work are discussed.