The sporadic occurrence of Echo virus types 27 and 31 in association with 
aseptic meningitis during the enterovirus seasons in Ontario in 1959 to 1962 is 
reported.The etiological significance of both of these isolates was verified by 
demonstration of type-specific serological response in meningitis patients. Echo 
27, which up to now has not been encountered in association with human illness, 
could be added to the list of viral agents capable of causing aseptic 
meningitis. Isolation of Echo 31 from cerebrospinal fluid provides definite 
proof of the etiological significance of this virus in cases of aseptic 
meningitis.