We performed a prospective study to see if positioning of the distal fragment in true neutral rotation could prevent the malrotation deformity following closed locked intramedullary nailing in femoral shaft fracture. True neutral rotation was ohtained hy aligning the posterior margins of both femoral condyles to the floor with the image intensifier. Four patients out of forty-one ( forty-three nailing ) developed the malrotation deformity of more than 15 degrees. Since true neutral rotation of the distal fragment alone can not prevent malrotation cleformity, femoral anteversion of normal side (if possible) must be checked beforehand and that of fractured side must be traced during the nailing procedure.