Neuroimaging has become one of the most important methods in the investigation of the neurobiological underpinnings of borderline personality disorder. Structural and functional imaging studies have revealed dysfunction in different brain regions which seem to contribute to borderline symptomatology. This review presents relevant studies using different methodologies: volumetry of limbic and prefrontal regions, investigations of brain metabolism under resting conditions, studies of serotonergic neurotransmission, and challenge studies using emotional, stressful, and sensory stimuli. Dysfunction in a frontolimbic network is suggested to mediate much, if not all of the borderline symptomatology.