Controlled trials of psychotherapy and follow-up studies of borderline personality disorder (BPD) have shown significant, but usually limited, improvement. We examined the hypothesis that BPD changes more slowly than nonborderline disorders. In a study of long-term dynamic psychotherapy, 16 subjects with BPD and 35 with non-BPD disorders were treated for a median of 3 years with a follow-up of 5 years. From periodic assessments, we calculated the rate of change for each subject over the course of the study on each measure of symptoms and functioning. At intake, borderline psychopathology was associated with higher levels on 76% of 17 measures of comorbid axis I disorders, symptoms, and functioning. BPD psychopathology was associated with faster (not slower) rates of improvement on three measures, but after controlling for the initial level of each measure, there were no significant associations. These findings counsel both optimism and patience in the long-term treatment of patients with BPD.