In psychiatric outpatients, the usefulness of the dimensional NEO-FFI as a screening instrument for personality disorders (PDs) was compared with the categorical screening instrument SAPAS-SR using the SCID-II as the gold standard. Major research questions are: 1) is the NEO-FFI a useful screening instrument for PDs? 2) does the NEO-FFI outperform a categorical screening instrument (SAPAS-SR)? 3) does combining both instruments improve the screening results? Extreme raising on Big Five personality trait domains (NEO-FFI) domain scores were examined in relation to the presence and the number of PDs as diagnosed, with to the SCID-II. Additionally, the NEO-FFI, in conjunction with a short self-report screening instrument (SAPAS-SR), was analysed with respect to sensitivity and specificity for screening of PDs. According to the SCID II, 97 patients (50%) were suffering from a PD. The majority of them had no (35.9%) or only one (40%) extreme score on one of the Big Five personality domains. There were no significant relationships between separate extreme traits on PD or five factor profiles, as proposed in the literature, and the presence of a SCID-II PD. Comparisons of the NEO-FFI with the SAPAS-SR showed no significant relationships. Using both screeners in conjunction resulted in an increase in specificity and the number of correctly classified cases at the expense, however, of the sensitivity. Correlation and regression analyses showed that personality traits are statistically significant predictors for each of the12 PDs. However, the associations between NEO-FFI scores and the DSM-VI-TR PD criteria were rather modest. Support could not be obtained for the view that separate extreme scores on basic personality traits or combinations of such scores in five-factor profiles will provide adequate screening possibilities for PDs. The SAPAS-SR has better screening potential than the NEO-FFI or the SAPAS-SR and the NEO-FFI together.