The current study compares the use of two alternative methodologies for using the Five-Factor Model (FFM) to assess personality disorders (PDs). Across two clinical samples, a technique using the simple sum of selected FFM facets is compared with a previously used prototype matching technique. The results demonstrate that the more easily calculated counts perform as well as the similarity scores that are generated by the prototype matching technique. Optimal diagnostic thresholds for the FFM PD counts are computed for identifying patients who meet diagnostic criteria for a specific PD. These threshold scores demonstrate good sensitivity in receiver operating characteristics analyses, suggesting their usefulness for screening purposes. Given the ease of this scoring procedure, the FFM count technique has obvious clinical utility.