Morphea, a localized form of scleroderma, is a chronic inflammatory autoimmune disease of the skin. Color Doppler Ultrasound has been reported as a reliable tool to assess the activity of the disease. With histologically confirmed cases, this case series describes a new ultrasound sign consisting of a hyperechoic halo surrounding superficial subcutaneous veins of the extremities in transverse view, named the sun sign. This sign can help diagnose morphea in the inflammatory phase and correlate in pathology with perivascular infiltrates surrounding superficial subcutaneous veins.