Mefloquine is an antimalarial drug with schizonticidal activity on blood-stage parasites. Studies of the role of mefloquine on the development of Plasmodium berghei ANKA in anopheles stephensi have been carried out that showed a dose-dependent effect on the sporogonic cycle of these parasites, with changes in the numbers of oocysts and the extent of sporozoite invasion of salivary glands. In this study, we show that mefloquine-resistant P. berghei ANKA blood stage parasites could be selected through drug pressure during continuous cyclical transmission of Anopheles gambiae s.l.