Respiratory samples (n=267) from hospitalized patients with respiratory symptoms were tested with real-time PCR, viral culture and direct immunofluorescence for RSV, influenza virus, parainfluenza viruses, and adenoviruses. Compared with conventional diagnostics, real-time PCR increased the diagnostic yield for these viruses from 24% to 43% and from 3.5% to 36% in children and adults, respectively.