An unusual serpentine, peripheral, congenital dermal sinus tract in the foot of a white boy, twelve years old, was treated successfully by excision. An attempt has been made to recapitulate the processes that led to the formation of the tract. It is postulated that this tract could have arisen from a local defect on the surface of the limb that, with growth of the limb bud and proliferation of ectodermal elements, became invaginated to form a sinus. Rotation of the limb bud might then have twisted the sinus about the leg, producing the tortuous course observed in the patient reported here.