A series of constant strain rate labortory experiments have been conducted to examine pore pressure stabilization of failure in Westerly granite. Stabilization is characterized by a gradual increase in axial displacement rate for several hundred seconds prior to failure followed by gradual, inaudible stress drop as the sample fails. In contrast, dynamic failure is characterized by a 20 second or less accelerating axial displacement followed by a sudden audible stress drop. Pore pressure stabilization was observed at ratios of pore pressure to confining pressure, &lgr;, greater than 0.5 or so. The transition between stable and dynamic failure shifted to lower values of &lgr; with increasing effective confining pressure and decreasing strain rate.