The results of the clinico-epidemiological and laboratory (TGP, tymol and HBsAg) investigations carried out in 164 contacts of an icteric case of viral hepatitis from a creche type children collectivity are presented. A wide spread of the infection, expressed by subclinical forms of disease identified on the basis of the alterations of TGP and their dynamics (27.4%) was pointed out. The increased incidence of HBsAg carriers and the correlation with the TGP increased values allowed the conclusion that the infection was caused by the hepatitis virus type B. The epidemiological investigation established that the infection was transmitted by direct contact favoured by children's close physical contact.