In terms of malaria prevalence, The Gambia can be divided into two strata: low prevalence in the western part and relatively high prevalence in the eastern part. Nevertheless, within these two strata, prevalence can vary substantially by village. Transmission is seasonal (August-December) and the country is working towards malaria elimiation. Coverage of interventions (LLIN, IRS, IPTp, SMC) is apparently good. Nevertheless, there is still some residual transmission that in the eastern part is moderate to high during the period August-December. Samples contributed by the malaria population biology group (MPB) of MRCG are from clinical infected malaria patients from across The Gambia and Southern Senegal. This study is integrated within the malaria programme grant (MPG) and the national malaria programme efficacy studies. It explores targeted and whole genome surveys of polymorphisms for association with in vivo and ex vivo anti-malarial drug response phenotypes of Plasmodium falciparum isolates from The Gambia to characterize mechanisms of drug resistance in P. falciparum. With the clinical and mass chemotherapeutic interventions by NMCP and MPG, monitoring for emerging and known markers of drug resistance will help determine if these antimalarial interventions have selected for parasites that are less susceptible to chemotherapies.