The authors describe the hospitalization and differential diagnostic procedure in a 5-month-old infant with acute respiratory distress syndrome. In the immunological picture there was deficiency in the area of specific cellular immunity combined with hypogammaglobulinaemia class G. Serological examination incl. anti-CMV IgG and IgM were negative. Post mortem histological examination revealed a congenital defect of cellular immunity and generalized cytomegalovirus infection.

        Key words: cytomegalovirus, acute respiratory distress syndrome, immunodeficiency