One function of working memory is to protect current mental processes against interference. In contrast, to be able to react flexibly on unpredictable environmental changes working memory should not totally be encapsulated from processing task unrelated information; that is, it should remain distractible. By manipulating the task load of the primary task in an auditory distraction paradigm we investigated how these opposing functions are coordinated by working memory. The behavioural results show that distraction effects were still present but reduced markedly with higher task demands. This suggests that working memory exerts some control over involuntary attention. In addition, event-related brain potentials related to the different processing stages reveal that the preattentive change detection system underlying distraction was not modulated by task demand whereas distraction per se was. The present data suggest that working memory is able to coordinate the maintenance of distractibility and the focus on the task at hand.