Dengue fever (DF) is a mosquito-borne acute viral disease presenting with hemorrhagic manifestations in severe cases. Southeast Iran is in close proximity to Pakistan, an endemic country for DF. This cross-sectional study was conducted in the Sistan and Baluchestan province in the southeast of Iran to investigate possibility of DF (immunoglobulin M [IgM], immunoglobulin G [IgG], and nonstructural protein 1 [NS1] antigen tests) in 60 clinically suspected patients (April 2013 to August 2015). NS1 protein was detected in 5% (N = 3), at least one of the antibodies (IgM and/ or IgG) was detected in 11% (N = 7) of the samples. Five patients identified as of acutely infected. There was a simultaneous presence of NS1 protein and IgG or IgM antibodies in 4% (N = 2) of patients. Previous studies show establishment of potential vectors in this area. These evidences support the hypothesis that DF can be a health concern in Southeast Iran with potential future outbreaks.