Although boredom can be regarded as a ubiquitous emotion in most educational settings, including foreign and second language classrooms, and this condition can have a detrimental effect on the process of learning, it has to a large extent escaped the attention of second language acquisition researchers dealing with individual learner differences. The study reported in this article sought to fill this gap by investigating the trajectories of boredom exhibited in a practical English class by 11 Polish university students majoring in English. The data were collected by means of a background questionnaire, the Boredom in Practical English Language Classes Questionnaire (BPELC), and an in-class boredom questionnaire, including a self-report boredom grid, an open-ended query and an evaluation of the class based on a semantic differential scale. It was found that general proneness to experience boredom in practical English classes translated into distinct patterns of boredom in the class in question. At the same time, it turned out that the individual trajectories in experiencing boredom often deviated from the general patterns, being shaped by unpredictable constellations of individual and contextual factors.