Objectives Serotype 2 of dengue virus (DENV-2) is the most prevalent cause of dengue fevers. In this study, the C-prM gene was used for specific detection of DENV-2 by RT-LAMP assay. The RT-LAMP assay was optimized using the Taguchi design of experiments. Results The efficiency of the assay in such optimal conditions resulted in 100% sensitivity, 100% specificity, and 100% overall accuracy for detection of 4 copies/mu L of the genome of DENV-2. In addition, the detection of 2 copies/mu L of the genome of DENV-2 was feasible, although the sensitivity was 50%. Considering the importance of the specific detection of the dengue virus serotypes, the cost-effective RT-LAMP approach can be used for rapid, specific, and sensitive detection of DENV-2. Conclusion RT-LAMP, as a cost-effective method, was optimized using Taguchi array approach for specific and rapid detection of DENV-2. Such methods can facilitate the diagnosis procedure in remote regions.