Communicable respiratory viruses as a causative factor of infectious complication in hemoblastosis and myelodepression were investigated in 51 patients (aplastic anemia--3, multiple myeloma--10, different patterns of acute leukemia--16, chronic leukemia--8 and non-Hodgkin's lymphoma--14). Our clinical evidence obtained with the aid of polymerase chain reaction featured genomes of adenoviruses, influenza A and B viruses, respiratory-scintillating virus and coronaviruses. On the whole, respiratory viral infections were detected in 27 (52.9%) patients: adenoviruses--23.5%, coronaviruses--13.7%, influenza A and B--5.9% and respiratory-scintillating virus--3.9%. In many cases, herpes was associated with viral respiratory infection. That pathology was most often triggered by severe neutropenia induced by chemotherapy.