We present an occlusion culling algorithm that leverages the unique characteristics of patch primitives within the hardware tessellation pipeline. That is, unseen patches are costly to compute, but easy to find screen space bounds for. Our algorithm uses the well known hierarchical Z-buffer approach, but we present a novel variant that uses temporal coherence to maintain lists of visible and occluded patches. Patches may be animated and have applied displacement maps. We also allow traditional triangle mesh geometry to serve as occluders. This makes our scheme ideally suited for patch based articulated character models, moving within a polygonal environment.