In Germany, the Internet is gaining increasing importance for laypeople as a source of health information, including information about vaccination. While previous research has focused on the characteristics of online information about vaccination, this study investigated the influence of relevant user-specific cognitive factors on users’ search behavior for online information about vaccination. Additionally, it examined how searching online for information about vaccination influences users’ attitudes toward vaccination. We conducted an experimental study with 56 undergraduate students from a German university that consisted of a survey and eye-tracking while browsing the Internet, followed by a content analysis of the eye-tracking data. The results show that the users exposed themselves to balanced and diverse online information about vaccination. However, none of the examined cognitive factors (attitude toward vaccination, attitude salience, prior knowledge about vaccination, need for cognition, and cognitive involvement) influenced the amount of time users spent searching the Internet for information about vaccination. Our study was not able to document any effects of attitude-consistent selective exposure to online information about vaccination. In addition, we found no effect on attitude change after having searched the Internet for vaccine-related information. Thus, users’ search behavior regarding vaccination seems to be relatively stable.