It is well known that virus hepatitis has been accidentally transmitted to persons inoculated with materials containing untreated human serum, plasma or blood. The possible accidental transmission of virus hepatitis without direct inoculation is a more recent concept. If a physician accidentally inoculates himself with virus-containing blood in the process of treating a patient, he is practically in an equivalent position with the patient receiving such material. However, the illness of the physician which might result would be classified as occupational. It is possible that a similar occupational situation may exist among technical personnel who merely handle serum, plasma or blood. If such a situation does exist, thousands of persons throughout the world are potentially involved. We are in a position to report 7 cases of apparent virus hepatitis which occurred among workers handling blood and its derivatives at Cutter Laboratories. All cases were provisionally considered industrial and have been