We tested predicted relationships (Widiger, 1993; Widiger, Trull, Clarkin, Sanderson, & Costa, 1994) between personality disorder scores and facets of the five-factor model, and evaluated the relative benefits of facet-level analyses over domain-level analyses. Data from 614 undergraduates indicated: (a) 63% of the predicted facet relationships were significant, although many unpredicted relationships also emerged; (b) facet-level analyses did not yield substantially stronger effect sizes than domain-level analyses; but (c) facet-level analyses provided much better discrimination between personality disorders than domain-level analyses. Facets of the openness to experience domain also helped discriminate between personality disorders, which is in contrast to previous domain-level findings that openness is not important.