The effect of anisotropy dispersion on the magnetization process in magnetoresistive sensor films is studied using micromagnetic calculation. It is assumed that the magnetization of the film is fixed at both ends to the track width direction, which corresponds to the average direction of the easy magnetization axis of the film. Magnetization distribution at different stages of the magnetization process is calculated by numerical integration of the Landau–Lifshitz–Gilbert equation. Our study shows that anisotropy dispersion causes buckling instead of coherent rotation of the magnetization. As dispersion increases, buckling becomes more pronounced. Furthermore, buckling does not completely disappear when the external magnetic field is weakened to a small value. The magnetization process is influenced by buckling, and this may lead to Barkhausen noise. ©1996 American Institute of Physics.