Twenty patients presenting with chronic ill-defined illnesses in a rural practice were investigated virologically. The only positive finding was the detection of elevated Coxsackie B titres in 16 of these patients. Three had experienced mainly cardiovascular symptoms; the remaining 13 are thought to have suffered from myalgic encephalomyelitis. This is a distressing and often prolonged illness, the cause of which is as yet unknown but is suspected of having a viral aetiology.