Our objective is to assess the characteristics of respiratory syncytial virus (RSV) infection in adult patients and to establish differences with influenza viruses. Fifty-four patients diagnosed with RSV and 198 with influenza were prospectively included. Compared with influenza, empirical antimicrobial therapy was more frequent in patients diagnosed with RSV, whereas antibiotic withdrawal at the time of diagnosis confirmation was lower (OR, 0.12; CI, 95% 0.01-0.90; P = 0.040). RSV-positive patients were more likely to need hospital readmission (OR, 3.00; CI, 95% 0.98-9.09; P = 0.053). The role of RSV infection in adults is often overlooked, leading to inappropriate use of antibiotics and a probable increase in nosocomial RSV transmission.