Objective: Application of realtime RT-PCR and conventional RT-PCR for detection of RSV in viral respiratory infections. Methods: Realtime RT-PCR and conventional nested RT-PCR were used to detect RSV on 110 respiratory samples collected from children with viral lower respiratory infections. Results: The data from the patients, whose samples were collected, showed that lower respiratory tract infections included bronchitis, bronchiolitis and pneumonia and that the mean of patient age was below 2 year old, among which, the negative RSV group of patients was 1.9 ±1.7 and the positive RSV group was 1.6 ± 1.4 years of age. The mean of time period from the onset of infections to sample collection was from 3.3 to 3.4 days. Realtime RT-PCR produced the same results as that of conventional RT-PCR. Conclusion: Realtime RT-PCR is rapid and closed-tube procedure; it should be used for detection of RSV in acute respiratory infections. Keywords: RSV, realtime RT-PCR, conventional RT-PCR