Objective: Respiratory viral infection of the neonatal period is highly contagious. Rapid and accurate diagnosis is important for proper treatment and prevention. However, the existing diagnostic method, respiratory virus cell culture, takes a long time to diagnose. Recent development of rapid diagnostic methods such as multiplex reverse transcriptase polymerase chain reaction (RT-PCR) enable early detection and effective treatment of respiratory viral infections. We compared the efficiency of multiplex RT-PCR and R-mix virus culture for rapid detection of respiratory viruses. Methods: We retrospectively analyzed the clinical features and results of R-mix virus culture and multiplex RT-PCR with nasopharyngeal aspiration specimens in 117 newborns admitted to neonatal intensive care unit suspected of infectious diseases. Results: R-mix virus culture was positive in 29 cases (24.8%) and RT-PCR in 86 cases (73.5%). R-mix virus culture and multiplex RT-PCR were identical in 54 cases (positive 26 cases, negative 28 cases). Among 75 cases that showed different results, 60 showed negative result in R-mix virus culture and positive result in multiplex RT-PCR, and three showed positive result in R-mix virus culture and negative result in multiplex RT-PCR. Different viruses were detected in the remaining 12 cases by both methods. Conclusion: Multiplex RT-PCR is faster than R-mix virus culture and has the advantage of identifying new respiratory viruses. On the other hand, Multiplex RT-PCR is more susceptible to false positives and mixed infections than R-mix virus culture, so more attention is required when interpreting test results.