Most malaria transmission in West Africa is by Anopheles funestus and An. gambiae s.l. An. funestus is not very polymorphic and is generally susceptible to currently used insecticides. An. gambiae in contrast is very polymorphic. On the basis of chromosomal polymorphism An. gambiae can be divided into forest and savannah forms. The savannah forms in turn exist as several types, viz. Bissau, Mopti and Bamako. Insecticide susceptibility does not correlate with chromosomal type in most cases; nevertheless, correct identification of vectors is necessary if a successful antimalarial campaign is to be developed. It is particularly important to determine which of the mosquitoes in the region under study are the important vectors of malaria. In the light of the difficulties encountered in mass vector control programmes, individual control measures such as home spraying and use of impregnated bed nets and curtains may be considered for malaria control.