Recently the term "enteroviruses" was introduced as descriptive of a large group of human viruses which includes the three polioviruses, the Coxsackie viruses, and the ECHO viruses.1These agents have many properties in common, including the ability to multiply in the human gastrointestinal tract with or without the production of clinical disease. Disease, when it does occur, most frequently involves the central nervous system (CNS). Classification of the enteroviruses into the three groups listed above has become more difficult as certain properties originally believed unique for one group are found to be shared by others. Further evidence of common pathogenic and serologic properties are presented in this communication. Numerous nonpoliomyelitis enteroviruses have been associated with aseptic meningitis, a subject recently reviewed by others.2A few paralytic illnesses have also been reported which were associated with nonpoliomyelitis enterovirus infections,3and some in combination with a poliovirus.4Present