Influence of a nonuniform anisotropy distribution on domain reversal dynamics in ferromagnetic thin films has been investigated. A micromagnetic model has been developed adopting a Monte Carlo algorithm to examine the thermally activated reversal process. In this study, the uniaxial magnetic anisotropy magnitude is spatially nonuniform, Interestingly, the simulation results demonstrate the crucial importance of the nonuniform anisotropy variation on the domain reversal dynamics, The reversal behavior is altered from wall-motion dominant to nucleation dominant with a small change in the spatial anisotropy distribution.