A case of progressive congenital hypertrophy of the feet was presented. From a diagnostic standpoint, this case was extremely challenging. Local gigantism was excluded from the diagnosis because the deformity was localized to both feet, with all components showing a concomitant increase in size. Furthermore, there was no evidence of neurofibromatosis or arteriovenous fistula formation. Other conditions leading to lower extremity hypertrophy, ie, Klippel-Trenaunay-Weber syndrome and other diseases associated with angiodystrophy, were excluded because of the absence of varicosities and cutaneous angiomas. There also was no evidence of an adrenal tumor or enchondromas. There was, however, a slight increase in the temperature of the left limb and an increase in the amount of vascular channels of the lower extremity, which may relate to an obscure form of angiodysplasia. Furthermore, the patient's mother took thalidomide during pregnancy, which has been shown to cause a large range of limb deformities. The authors believe that it is appropriate to classify this case as an idiopathic form of progressive congenital hypertrophy, localized to the feet of a 25-year-old Caucasian female. The goal of treatment is primarily two-fold. First, progressive narrowing of the forefoot should be obtained through closing wedge osteotomies. Second, multi-stage debulking of the muscle tissue should be performed, with associated skin reductions. The authors believe that this is the first reported case of bilateral muscular and bony hypertrophy of the feet, which was present at birth and continued to increase after the cessation of skeletal growth.