In February 2004, we initiated an epidemiological investigation within a US state to enhance autopsy surveillance for clinically suspected prion disease. During the first 30 months, 30 cases of suspected prion disease were referred from throughout Washington. Of these, 18 cases had prion disease, and all of these were classified as either familial or sporadic Creutzfeldt-Jakob disease (CJD); there was no case of variant CJD. This represents a death rate of approximately 1.1 cases of sporadic CJD per 1 million people per year in Washington. Our results do not support the hypotheses that variant CJD is an emerging illness in Washington or that sporadic CJD is more common in this state than in other regions of the world.