It is possible to conduct an analysis of the incidence of viral diseases in calves if these diseases are divided into two basic groups. One group comprises diseases of respiratory organs which are manifested by symptoms of a respiratory syndrome, and the second group comprises diseases of digestive tract organs in the form of a gastrointestinal syndrome. It is considered that viruses have the dominant role in the complex etiology of the respiratory syndrome, primarily the IBR virus or the Bovine Herpes Virus-1 (BHV-1), followed by the parainfluenza 3 virus (RSV), the Bovine Viral Diahrrea Virus (BVDV), the bovine Respiratory Syncytial Virus (RSV), but also other viruses, such as adenoviruses, rhinoviruses, coronaviruses, can also influence the appearance of the respiratory syndrome. The respiratory syndrome is rarely caused by a single viral agent, but most frequently by mixed viruses, but also by bacterial infections. Mixed viral infections often have a lethal outcome. Investigations of the etiology of the gastrointestinal syndrome so far indicate that, in addition to bacteria, viruses can also be a significant etiological factor. Rotaviruses, coronaviruses, adenoviruses parvoviruses, herpesviruses (the IBR virus), pestiviruses (BVDV), can be the causes of a gastrointestinal syndrome. It is believed that viruses can be the cause in about 10% cases in the ethiopathogenesis of this syndrome. The paper describes the etiopathogenesis of calf diseases of viral etiology which are most often found in the local conditions of industrial breeding of calves.