In the present study, an in-house-developed real-time RT-PCR (rRT-PCR) for serotyping of dengue virus (DENV) was evaluated for its performance, using 612 clinical samples. Compared to the composite reference standard, the in-house-developed rRT-PCR had an overall sensitivity of 97.5% and a specificity of 100%. The assay had a sensitivity of 100%, 95.6%. 96.9% and 100% for detecting DENV-1, DENV-2, DENV-3 and DENV-4, respectively. We recommend periodic evaluation of real-time RT-PCR assays for detecting DENV serotypes with a large number of samples and the use of at least two assays that target different regions of DENV genomes.