Usability has become an imperative aspect of survival on the web, thus, it has always been considered as a crucial aspect of web design. This paper presents the results of a study that compared two think-aloud usability testing methods: the concurrent think-aloud and the retrospective think-aloud methods. Data from task performance, testing experience, and usability problems were collected from 40 participants equally distributed between the two think-aloud conditions. The results found that while the thinking aloud method had no impact on task performance and participants testing experience, participants using the concurrent think-aloud method detected a larger number of minor problems with the test interface than participants using the retrospective think-aloud method. These findings suggest a reason for preferring the concurrent think-aloud method to the retrospective one.