Embalmed tissues are adequate for the detection of JC virus in lesions of progressive multifocal leukoencephalopathy (PML) by immunohistologic and molecular methods. JC virus was readily detected in embalmed brain tissue using immunohistochemistry (IHC), in situ hybridization (ISH), and the polymerase chain reaction (PCR). Two brains were removed from bodies that had been embalmed at least 24 h prior to autopsy. They were subsequently post fixed in 10% buffered formalin for 10-14 days before dissection and molecular studies were performed. Though these techniques are not novel, their use in embalmed tissues is. Routine embalming should not eliminate these diagnostic procedures from consideration.