In this paper, we describe orthodontic treatment in a patient with Down's syndrome accompanied by reverse occlusion due to skeletal deformity with unilateral cleft lip and alveolus. Orthodontic treatment was not initially indicated due to the potential need for surgical intervention and the presence of mental retardation. The further mental and physical growth of the patient together with the help of their guardians, however, allowed placement of a multi-bracket. Although no skeletal correction occurred as a result, reverse occlusion was corrected by labial inclination of the incisors. The patient and her guardians were satisfied with the correction of the overlap by orthodontic treatment alone.