Baseline surveys were conducted in Khartoum State, Sudan, during the rainy season (end of July to the beginning of September) in 2008, and female mosquitoes were sampled for arboviruses from November 2008 to January 2009 to predict outbreaks of Rift Valley Fever (RVF) in Khartoum State. Aedes vittatus (Bigot) and Ae. vexans (Meigen) vectors were found only at one of the study sites (Soba West). Under laboratory conditions, survival of these mosquitoes exceeded the mean incubation period of the arboviruses in these vectors (15 days). Field-collected blood-fed female mosquitoes were tested for the RVF virus using the real-time PCR technique. The virus was detected in populations of Ae. vexans and Culex quinquefasciatus (Say) for the first time in Sudan.