We present a novel method for real-time collision detection of patch based, displacement mapped objects using hardware tessellation. Our method supports fully animated, dynamically tessellated objects and runs entirely on the GPU. In order to determine a collision between two objects, we first find the intersecting volume of the corresponding object oriented bounding boxes. Next, patches of both objects are tested for inclusion within this volume. All possibly colliding patches are then voxelized into a uniform grid of single bit voxels. Finally, the resulting voxelization is used to detect collisions. Testing two moderately complex models containing thousands of patches can be done in less than a millisecond making our approach ideally suited for real-time games.