We report two separate naturally occurring cases of fatal herpesviral disease in Cooper's Hawks (Accipiter cooperii). Gross lesions included splenomegaly and hepatomegaly, with diffuse pale mottling or scattered small white foci. Histologic lesions included splenic and hepatic necrosis associated with eosinophilic intranuclear inclusion bodies characteristic of herpesvirus. In one case, necrosis and inclusions were also noted in bone marrow, thymus, bursa of Fabricius, thyroid gland, parathyroid gland, ceca, and the enteric system. Transmission electron microscopy demonstrated viral particles typical of herpesvirus within hepatocyte nuclei and budding from the nuclear membrane. Herpesviral DNA was amplified via polymerase chain reaction (PCR) of paraffin-embedded liver and spleen, and sequence data were consistent with columbid herpesvirus-1, an alphaherpesvirus of Rock Pigeons (Columba livia). PCR results provide evidence that this disease is transmitted to raptors via Rock Pigeons, most likely through ingestion of Rock Pigeons as prey.