A Cochrane review included 8 studies with a total of 1 996 subjects. All were conducted in areas with low malaria transmission, seven in South-East Asia and one in the Peruvian Amazon. The doses and dosing regimens of artesunate and mefloquine varied across trials. The trials using a total dose of 25 mg/kg mefloquine and 10 mg artesunate reported fewer treatment failures with the combination at all time points: day 28 (RR 0.17, 95% CI 0.06 to 0.47; 824 participants, 4 trials), day 42 (RR 0.23, 95% CI 0.14 to 0.39; 298 participants, 1 trial), and day 63 (RR 0.26, 95% CI 0.09 to 0.77; 501 participants, 2 trials). The results for parasitaemia showed a similar trend. Trials using a lower dose of artesunate tended to favour the artesunate plus mefloquine combination. Overall, adverse events were similar across treatment arms.