The frequency and types of DSM-III personality disorders (PDs) were investigated in a sample of 26 recent-onset bipolar-disordered (BD) patients. Results showed that 62% of BD patients had PDs according to the Structured Interview for DSM-III Personality Disorders (SIDP). The most frequently diagnosed PDs were the histrionic, borderline, passive-aggressive, and antisocial categories. A comparison between the BD patients and a sample of 35 recent-onset schizophrenic patients showed significant differences for two PDs. Schizotypal PD was more frequently diagnosed in the schizophrenic group, while the BD group had a higher frequency of histrionic PD.