Non-union of tibia is known to be a common complication after fracture both bones of leg treated conservatively. During the course of natural healing, fibula usually unites early as it had more soft tissue attachment and vascular supply. Due to early union of fibula and absence of axial force across the tibia, it undergoes non-union.Two cases, a 32-year-old male and 65-year-old female treated conservatively for fracture both bones of leg long years back, presented to us with mild calf pain on and off. On radiological examination, there was non-union of tibia along with compensatory fibular hypertrophy to the extent that fibula became main weight bearing bone.In both the cases, we observed gross fibular hypertrophy in presence of non-union of tibia.In conservatively treated cases of fracture, both bones of leg, non-union of tibia may coexist with compensatory hypertrophy of fibula to the extent that, it becomes main weight bearing bone of the leg.We are presenting here two cases of natural tibialization of fibula along with nonunion tibia. Our article supports the theory of Wolff's law.