This short-term, open-label study investigates short- and long-term effects of the selective serotonin reuptake inhibitor (SSRI) fluvoxamine for the treatment of trichotillomania (TTM). Additionally, this study aimed to test the hypothesis that the presence of hair pulling compulsiveness is predictive of SSRI response. Nineteen subjects meeting the Diagnostic and Statistical Manual of Mental Disorders, Third Edition Revised, (DSM-III-R) criteria for TTM were treated with fluvoxamine at doses up to 300 mg/day. Random regression analysis of change across time for patients who completed the study (n=14) and those who dropped out (n=5) revealed statistically significant improvements in Physician Rating Scale, hair-pulling episodes, Trichotillomania Impairment Scale, and Trichotillomania Symptom Severity Scale, but not in estimated amount of hair pulled. In addition, the percentage of patients' focused or compulsive hair-pulling symptoms was predictive of treatment response. Unfortunately, all three subjects who entered long-term treatment displayed substantial movement back toward baseline by the end of 6 months. We concluded that fluvoxamine produces moderate reductions in symptoms during the short-term treatment of TTM and that the presence of focused or compulsive hair pulling may be predictive of treatment response. However, responses may be short lived when treatment is extended.