Elastosis perforans serpiginosa (EPS) is a rare perforating dermatosis in which elastic fibers extrude from the papillary dermis producing umbilicated papules, characteristically arranged to form arciform or serpiginous patterns on the skin. It can be observed in patients with Down's syndrome, in whom in some cases the disease has been reported to be more widespread and to run a longer course. We present the case of a 20-year-old girl with Down's syndrome, hypothyroidism, acne and hypertrichosis, who had a 2-year history of multiple atrophic lesions with an arciform pattern on the distal extensor portions of both thighs, histologically showing the typical features of EPS.