A new physical mechanism of plastic deformation in nanowires is suggested and theoretically described. This mechanism represents collective formation of nanodisturbances - nanoscopic areas of plastic shear with tiny shear vectors - in deformed nanowires. We calculated the energy characteristics for collective nanodisturbance formation and compared them with those for conventional dislocation generation and our earlier model of similar mechanism. It is shown that the deformation mode via collective nanodisturbance nucleation can dominate in Au nanowires deformed at high stresses and zero temperature.