Early detection of exotic mosquito species (EMS) is of vital importance to prevent local transmissions of mosquito-borne diseases. From 2017 to 2020, the Belgian federal government and regional authorities funded the MEMO project (Monitoring of Exotic MOsquitoes in Belgium), which aimed at detecting and evaluating the occurrence of EMS in Belgium. During the project 52,478 mosquitoes were collected at 23 points of entry. In order to implement management strategies, especially regarding potential disease vectors, accurate and reliable species-level identification of all mosquito life stages is essential. Therefore, morphological species identifications of a subset of samples, including all EMS, were validated using molecular techniques. About 3,300 specimens were barcoded using multiple markers to obtain an identification at species level (COI, ITS2, ACE2, CQ11). To this end, a DNA-based species identification pipeline was established that allowed for the reliable determination of the majority of the native (n=31) and all six EMS of main concern to Europe. To distinguish native species complexes (nsp=6) alternative markers are being investigated. EMS were found to enter Belgium repeatedly through different introduction pathways. The DNA-based pipeline has proven its usefulness to validate the morphological identifications and confirm the presence of EMS, especially in case of damaged specimens or immature stages like eggs.