Introduction: Viral respiratory infections (VRI) are a frequent cause of morbidity among adult population. Respiratory syncytial virus (RSV) produces 20% of VRI, however diagnosis is limited for a low sensitivity of conventional (FDA and ELISA) tests. Aim: To assess the impact of real time reverse transcriptase-polymerase chain reaction (real time RT-PCR) technique in RSV diagnosis in adult hospitalized patients; to characterize RSV infection among these patients. Patients and Methods: All adults hospitalized in Hospital Clinico Universidad Catolica during 8 weeks of winter season, with clinical picture of VRI, and with negative DFA for influenza A and B, parainfluenza 1, 2, 3 and adenovirus were included. Real time RT-PCR was performed from nasopharyngeal sample. Clinical information, general laboratory exams and chest X ray reports were collected. Results: Out of 114 patients with negative DFA, 17 (14.9%) Debe decir: RSV cases were demonstrated using real time RT- PCR. Fever, pharyngeal congestion, cough and bronchial obstruction were present in 80% of patients. Thirty percent of them had a baseline chronic disease and 47% were immunocompromised. One out of 17 patients (6%) required mechanical ventilation. No mortality was observed. Conclusions: Use of RT-PCR allowed increasing detection of RSV infection over 100% among adults with VRI without virological diagnosis with conventional techniques. It is necessary to consider RSV RT-PCR test among patients with clinical picture of VRI during RSV season, with negative virological screening tests.