The current study examined how specific neurological systems contribute to the expression of multiple personality dimensions. We used individuals with traumatic brain injuries to examine the contribution of the dorsolateral prefrontal cortex (DLPFC)--a region important for executive function and attention-to the expression of neuroticism and conscientiousness factors and facets. Results from Voxel-Based Lesion-Symptom Mapping analyses revealed that focal damage to the left DLPFC (Brodmann's area 9) was associated with high neuroticism and low conscientious factor and facet scores (anxiety and self-discipline, respectively). Compared with lesioned and normal controls, veterans with damage in left DLPFC also reported higher neuroticism and lower conscientiousness facet scores, slower reaction times on the California Computerized Assessment Package assessment, and lower scores on the Delis-Kaplan executive function battery. Findings suggest that while neuroticism and conscientiousness remain psychometrically independent personality dimensions, their component facets may rely on a common neurocognitive infrastructure and executive function resources in general.