A duplicated 3'-truncated version of RanGAP was previously identified as Segregation distorter (Sd), the meiotic drive gene in Drosophila melanogaster. Here we report the cloning and characterization of the complete gene sequence for the RanGAP homolog from the mosquito Aedes aegypti. The 1995 bp cDNA sequence consists of a 113 bp 5' UTR and 130 bp 3' UTR, and encodes a 583 amino acid protein with high sequence identity with RanGAP homologues of several species. A 20,125 bp genomic DNA sequence contains the complete RanGAP gene, consisting of three exons and two introns. Intron 2 comprises 18,082 bp and contains multiple repetitive elements as well as putative coding regions. The RanGAP locus was mapped to the q-arm of chromosome 2. Because the meiotic drive gene (M(D)) in A. aegypti was previously shown to be tightly linked with the sex determining locus on chromosome 1, RanGAP is likely not the M(D) gene.