Malaria is an infectious decease caused by a one-celled parasite called Plasmodium. The most common types are falciparum and vivax malaria where falciparum is the deadliest form of malaria infection. Malaria is present in almost all tropical and sub-tropical regions around the world and there are at least 300 million cases of malaria in the world with over a million deaths every year. Some of the most frequently used antimalarial drugs are chloroquine, amodiaquine and sulphadoxine-pyrimethamine but drug resistance of the plasmodium falciparum parasite is spreading. The situation is especially serious in Southeast Asia where multi-drug resistant falciparum malaria is widespread. One factor that adds to drug resistance is poor compliance with dosing schedules. There are also increasing problems with counterfeit drugs that contain none or to low amount of antimalarial drug and this will also speed up drug resistance. It has recently become more common to combine different antimalarial drugs, preferably using drugs with different mechanisms of action, in order to increase efficacy and reduce the spread of malarial drug resistance within the malaria parasite populations. The aim of the developed screening method is to determine drug use in areas where a change in treatment policy has taken place since this would be more accurate than interviewing patients. Several of the drugs included in this screening method have relative long half-life e.g.chloroquine, pyrimethamine, mefloquine, and lumefantrine that are detectable at least 7 days after administration. Solid phase extraction is used as sample clean-up of plasma samples and separation is performed with gradient-LC and UV-detection at two different wavelengths. The developed method will be presented together with detection limits of the various drugs.