Abstract The purpose of the present study was to examine the developmental patterns of Cloninger's biogenetic character traits in subjects with borderline personality disorder (BPD). Study subjects met Diagnostic and Statistical Manual of Mental Disorders (3rd edn, revised; DSM-III-R) criteria for BPD without comorbid axis I or II disorders, as determined by the Diagnostic Interview for Borderlines-Revised, Structured Clinical Interview for the DSM-III-R, and Diagnostic Interview for Personality Disorders. The BPD subjects and age- and sex-matched healthy comparison subjects were initially interviewed for Cloninger's biogenetic characters and re-interviewed at an interval of 1 year for the following 3 years. There were significant differences in the developmental patterns of self-directedness, cooperativeness, and self-transcendence between BPD and healthy comparison subjects (significant group by time interaction: repeated measures manova, F = 17.3, d.f. = 3,240, P < 0.001; F = 28.5, d.f. = 3,240, P < 0.001; F = 4.7, d.f. = 3,240, P < 0.01, respectively). The BPD subjects had less changes in character-related maturity with increasing age than did healthy comparison subjects. Post-hoc tests with Duncan's statistics revealed that subjects with BPD had significantly lower scores on self-directedness at all assessment time periods (P < 0.01) and lower scores on cooperativeness at the second-year and third-year follow-up assessments as compared to healthy comparison subjects (P < 0.01). The BPD subjects had a distinctively different developmental pattern of Cloninger's character compared to healthy comparison subjects. The character development of BPD patients was more fixed and immature than those of healthy comparison subjects.