Enteroviruses are considered to be the most common agents implicated in myocarditis and cardiomyopathy. Recent studies have suggested persistent enterovirus infection in chronic disease showing the presence of enteroviral RNA in the myocardium. We used gene amplification by PCR which can demonstrate directly the presence of enteroviral sequences in endomyocardial biopsies. The primers were chosen in the 5' non-coding region of the genome representing highly conserved sequences among enteroviruses and therefore allowed the amplification of the majority of enteroviruses. The hybridization of the amplified products was effected with specific general riboprobe derived from 5' non-coding sequences internal of the amplified fragments. The results include 105 patients distributed in 6 groups: 45 idiopathic dilated cardiomyopathies with 66.7%, 17 alcoholic cardiomyopathies with 52.9%, 10 myocarditis with 30%, 5 multifactorial cardiomyopathies with 40%, 5 patients with immunosuppressive therapy with 100%, and 23 control group without viral etiology with 39.1% positive samples. The study suggested a positive link between viral infection and cardiomyopathies, but did not allow a direct relation between enterovirus infection and idiopathic dilated cardiomyopathy to be established.