Generalized hypertrichosis is a common side-effect of oral minoxidil treatment for hypertension. However, hypertrichosis is uncommon after treatment with topical minoxidil for alopecia, and normally only occurs in areas close to the site of application. A 16-year-old girl is presented who developed generalized hypertrichosis 3 months after applying topical minoxidil for treatment of diffuse alopecia in doses greater than that prescribed. Four months after discontinuing treatment, the abnormal hair gradually diminished and disappeared.