A peculiar nucleotide sequence of HEV RNA was recovered from a wild boar (Sus scrofa leucomystax ) of male sex with about 10 kg of body weight, captured 1-Feb-2009 in the forest of Tenryu-ku, Hamamatsu, Shizuoka, Japan. The sequence (JBOAR135-Shiz09, accession number AB573435) showed only less than 80% nucleotide identity to so far reported sequences of HEV genotype 1 through 4 (72.7-76.4% vs G1, 75.5% vs G2, 71.2-78.2% vs G3, 74.9-78.2% vs G4) and also to the rabbit HEV isolates recently reported from China (75.5-77.3%). Since the rabbit HEV segregates to genotype 3 in the present phylogenetic analysis (CLUSTALW Unrooted N-J Tree Method), we propose our JBOAR135-Shiz09 isolate as the first member of new genetic group of HEV, "genotype 5".