We describe a 15-year-old girl with biopsy-proven morphea who developed progression to systemic disease 2 years after initial presentation. In contrast to other reported patients with localized scleroderma, some of whom have had mild, nonprogressive systemic involvement, this patient developed severe, debilitating disease, with skin tightness, sclerodactyly, esophageal involvement, restrictive pulmonary disease, and myopathy. From the time of her initial evaluation, the patient was positive for antinuclear antibodies (ANA), which were shown to be primarily directed against the Ku antigens. This observation suggests that ANA may be a prognostic indicator for progression to systemic disease.