The genome sequence of a duck hepatitis virus type 1 (DHV-1) strain was determined. Comparative sequence analysis showed that the genome possesses a typical picornarivus organization and also exhibits several unique features, such as the similarity of internal ribosome entry site to that of Porcine teschovirus 1 and Hepatitis C virus, the presence of a longest 3' untranslated region and a shorter leader protein in the Picornaviridae, the absence of a predicted maturation cleavage of VP0, the association of an aphthovirus-like 2A1 and parechovirus-like 2A2, and the unprecedented presence of an AIG1 domain in the N-terminus of 2A2. It is concluded that DHV-1 belongs to a new group of the family Picornaviridae that may form a separate genus most closely related to the genus Parechovirus.