The authors studied two cases of persistent axial artery of the lower limb, a classic but exceptional variation (42 cases in the literature). It is well explained by embryology and is a recapitulation of anatomy in the animal series. By the systematic study of the literature, we can isolate four distinct types: Type I: Complete axial artery, normal femoral artery. Type II: Id., but incomplete femoral artery, with two subdivisions: II a: Femoral artery is present but incomplete. II b: Femoral artery is absent. Type III: Axial artery only in the proximal zone. Type IV: Axial artery only in the distal zone. In these two last types, the femoral artery is complete. The I, III and IV types correspond to organogenetic perturbation at the stage 21 of Streeter. The type II implies a more early disturbance, prior to stage 18.