Respiratory viral infections constitute the most frequent reason for medical consultations in the World. They can be associated with a wide range of clinical manifestations ranging from self-limited upper respiratory tract infections to more devastating conditions such as pneumonia. In particular, in serious cases influenza A leads to pneumonia, which is particularly fatal in patients with cardiopulmonary diseases, obesity, young children and the elderly. In the present study, we show a protective effect of the low-molecular weight compound Ingavirin (6-[2-(1H-imidazol-4-yl)ethylamino]-5-oxohexanoic acid) against influenza A (H1N1) virus, human parainfluenza virus and human adenovirus infections in animals. Mortality, weight loss, infectious titer of the virus in tissues and tissue morphology were monitored in the experimental groups of animals. The protective action of Ingavirin was observed as a reduction of infectious titer of the virus in the lung tissue, prolongation of the life of the infected animals, normalization of weight dynamics throughout the course of the disease, lowering of mortality of treated animals compared to a placebo control and normalization of tissue structure. In case of influenza virus infection, the protective activity of Ingavirin was similar to that of the reference compound Tamiflu. Based on the results obtained, Ingavirin should be considered as an important part of anti-viral prophylaxis and therapy. © 2011 by the authors; licensee MDPI, Basel, Switzerland.