The transient gyromagnetic behavior of the one-dimensional 180°Bloch walls in thin films is analyzed based on the Landau-Lifshitz equation for distributed systems. The physical model of gyromagnetic spin motion in the wall is found adequate in explaining wall streaming (or worm motion). The key mechanism is the induction of a large transverse magnetostatic field resulting from discrepancy in switching speeds in the wall and the adjoining regions. The dependence of wall displacement on pulse shapes and film parameters is examined. © 1968 The American Institute of Physics.