Angioma serpiginosum (AS) is a rare acquired vascular lesion involving the superficial capillaries. The skin lesions usually presents in the first two decades of life and female are more affected. A typical lesion is characterized by deeply red non-palpable puncta that are grouped closely together in a macular or netlike pattern on the lower extremities and buttocks. A 10-years-old woman came to our clinic with purputic confluented macules on her left leg and thigh which had been present for about 2 years. Her lesions looked like portwine stain involving one leg, but in close observation, the lesions showed punctated appearance. In dermoscopy, numerous small, relatively well-demarcated, round to oval red lagoons were detected. A punch biopsy was done and histopathology of the specimen showed lobular proliferation of dilated capillary vessels arrranged in the papillary dermis. We concluded her lesions as AS on the base of dermoscopic finding and histopathologic features. We treated her with a 595nm pulsed dye laser(PDL). Unlike other portwine stains that require multiple laser treatments, it showed dramatic response to just single treatment. We suggest that dermoscopy is beneficial in the diagnosis of angioma serpiginosum due to its characteristic well-deparcated globules. Also, AS lesions are expected to have a very good response to pulsed dye laser due to its superfical location of vessels.