The karyotype of Aedes mediovittatus consists of 3 submetacentric pairs (2n=6). The average length of the metaphase chromosomes are: I=6.92 mm, II=10.06 mm, and III=13.71 mm. Average arm ratios are: I=1.097, II=1.122, and III=1.300. Somatic pairing is evident in all three pairs of mitotic chromosomes.