Research implicates the emotion of disgust in particular anxiety disorders, but possible processes by which disgust can cause anxiety have not been articulated. We review data from studies of the functional neuroanatomy of disgust in order to elucidate possible processes by which disgust can cause anxiety disorders. First, we examine whether fear and disgust involve different neural substrates. Despite inconsistencies, the data suggest that the amygdala is critical for fear and the anterior insula is critical for disgust. Second, we examine whether the anterior insula fits into current neurobiological models of fear and anxiety. Recent research suggests that the insula projects to neural circuits underlying fear and anxiety and is also involved in activation of the hypothalamic-pituitary-adrenal axis stress response. Additionally, the insula may mediate interoceptive awareness, a critical component underlying anxiety. These functions of the insula provide possible routes by which disgust interacts with and sensitizes the fear and anxiety circuits in order to produce pathological anxiety. The derived temporal routes of disgusts role in anxiety foster testable predictions that may help future research determine if and how disgust functions in anxiety.