Distractibility, which can be defined as an attention deficit in which orientation toward irrelevant targets can be hardly inhibited, is commonly related to a dysfunction of the dorsolateral prefrontal cortex. Here, we show that increased distractibility, observed in a patient with an exceptionally small lesion located in the upper brainstem, may result from the interruption of a direct tract that connects the prefrontal cortex to the superior colliculus, a structure involved in both eye movement control and attentional shifts.