Emergence of malaria parasite drug resistance is a serious problem in malaria control. Artemetherlumefantrinern(CoartemÂ®) is used as a first line treatment for uncomplicated falciparum malaria sincern2004 in Ethiopia. The objective of the study was to assess the efficacy of CoartemÂ® againstrnfalciparum malaria in Halaba Special Woreda, Southern Ethiopia. 5922 individuals that werernclinically suspected of malaria were screened for infection. Giemsa stained thin smears were used forrnidentification of Plasmodium species, and thick smears for detection and quantification of thernparasites. Among the screened, 1826 (30.8%) were malaria positive, of which 273 (14.9%) were duernto Plasmodium flaciparum and 1553 (85.1%), due to Plasmodium vivax. Among Plasmodiumrnflaciparum positive patients, 89 (32.6%) fulfilled the inclusion criteria and were enrolled in the study.rnHaemoglobin concentration of the study participants was measured on days 0, 14 and 28 usingrnportable spectrophotometer. Study outcomes were classified as early treatment failure (ETF), laternclinical failure (LCF), late parasitological failure (LPF) and adequate clinical and parasitologicalrnresponse (ACPR). Out of the 89 study participants, 6 (6.7%) were lost to follow up and 3 (3.4%)rnwithdrew from the study. Following drug administration, parasitemia cleared from all the studyrnparticipants on day 3, and almost all fever cleared on day 2. Gametocytes were detected in 9% of thernstudy participants on the day of inclusion into the study, and none could be detected after day 7.rnDuring follow up, one patient became positive for Plasmodium flaciparum, amounting to a 1.3% LCF,rnas a result of which the cure rate of CoartemÂ® in the study area was 98.7% (95% CI=93.2-100%).rnHowever, as a confirmation of emergence of CoartemÂ® resistance in the study area, it will bernnecessary to do a PCR correction to determine whether the 1.3% LCF was a new infection or arnrecrudescence. The mean haemoglobin level of the study participants was 10.8g/dl (Range: 9.2g/dl-rn13.7g/dl) on day 0, of which 57.3% were anemic. On day 28 of follow up, mean haemoglobin levelrnsignificantly increased (P=0.002), compared to day 0, and the proportion of anemic individualsrndeclined. The overall findings of the study have shown high efficacy and safety of CoartemÂ® forrntreatment of uncomplicated falciparum malaria, in the study area. Also, the high prevalence of P.rnfalciparum and P. vivax malaria, detected in the study area, indicated the ineffectiveness of the controlrnmeasures in practice. Therefore, the malaria situation in Halaba Special Woreda requires initiation ofrnmore effective integrated control measures and periodic monitoring of anti-malarial drug efficacy.rnKey words: CoartemÂ®, falciparum malaria, fever clearance, gametocyte clearance, Halaba SpecialrnDistrict,Parasiteclearance,Haemoglobin