The rationales given for studies of the population genetics of vectors are usually: (1) to predict the spread of genes, such as genes conferring insecticide resistance or possibly refractoriness to parasites and (2) to reveal novel insights into the epidemiology and transmission of vector-borne disease. The successful genetic transformation of mosquitoes has highlighted the need for a critical assessment of the rapidly accumulating body of data on the population genetics of malaria vectors. This article assesses how successful molecular genetic techniques have been in revealing new population patterns.