We developed the MGH Hairpulling Scale to provide a brief, self-report instrument for assessing repetitive hairpulling. Seven individual items, rated for severity from 0 to 4, assess urges to pull, actual pulling, perceived control, and associated distress. We administered the scale to 119 consecutive patients with chronic hairpulling. Statistical analyses indicate that the seven items form a homogenous scale for the measurement of severity in this disorder.