We model the spatial and temporal evolution of seismicity during the 1997 Umbria-Marche seismic sequence in terms of subsequent failures promoted by fluid flow. The diffusion process of pore-pressure relaxation is represented as a pressure perturbation generated by coseismic stress changes and propagating through a fluid saturated medium. The values of isotropic diffusivity range between 22 and 90 m2/s. The calculated value of anisotropic diffusivity (Daniso = 250 m2/s) is largest along the average strike (N140¿) direction of activated faults. Our results suggest that the observed spatio-temporal migration of seismicity is consistent with fluid flow.