Hepatitis E is an infectious viral disease with clinical and morphological features of acute hepatitis. The disease represents an important public health problem in developing countries, where it is often related to outbreaks mainly associated with consumption of contaminated water. During recent years, an increasing number of sporadic cases have also been described in industrialized countries. Besides humans, the hepatitis E virus (HEV) has also been identified in animals. In 1997, the virus was first detected in swine, and is now considered ubiquitous. Human and swine HEV strains from the same geographical region present a high level of nucleotide identity, and experimental infections have confirmed the cross-species transmission of swine strains to humans and of human strains to non-human primates. Studies on anti-HEV antibodies detection have demonstrated that people working in contact with swine or wild boar have a higher risk of infection than normal blood donors. In Japan and more recently in France, cases of hepatitis E have been associated with ingestion of uncooked meat from pigs, wild boar, or deer. The disease is currently considered an emerging zoonosis.