The internet is an increasingly popular source of consumer health information (CHI). Worldwide, millions of people regularly visit CHI websites to seek answers to medical issues, either for themselves or their loved ones. As CHI websites play such a vital role in people’s health behaviour, the evaluation of these sites has often been addressed in scholarly studies. The vast majority of these studies have focused on evaluation methods for assessing the quality of CHI websites (expert testing). While this emphasis on quality is understandable – health information needs to be accurate and up-to-date – calls are increasingly made to not only ensure the quality of information on CHI websites, but to also focus on the usability of these sites. This paper offers a review of the usability studies that have so far been conducted regarding CHI websites. We will discuss the potential of, in particular, observational user-driven research for CHI websites, by discussing the methodological drawbacks of the existing usability studies. In addition, we will examine the role of user characteristics in the evaluation of CHI web sites. The results of our review indicate that observational user research, when conducted properly, may offer valuable insights that complement those gained by means of expert testing.