Acquired constriction ring syndrome is a clinical condition of infancy characterized by circumferential constriction of a toe or another appendage, such as fingers and genitalia. The foot and ankle specialist should be aware of this condition because vascular obstruction of the affected appendage can rapidly lead to gangrene and autoamputation. Treatment consists of prompt identification and removal of the constricting foreign material. Although this condition is uncommon, it can lead to digital loss. Early treatment yields a good prognosis. A case report is presented of a 9-week-old infant who experienced acquired constriction ring syndrome caused by a strand of hair wrapped around the third and fourth toes that was treated by unwinding the hair under loupe magnification. (J Am Podiatr Med Assoc 96(3): 253–255, 2006)