The efficacy of the combination of artemether with doxycycline or azithromycin was evaluated in 60 patients with acute uncomplicated falciparum malaria who attended malaria clinic in Mae Sot, Tak Province (Thai-Myanmar border). Patients (30 each) were randomized to receive (a) 300 mg artemether together with 100 mg doxycycline as initial doses, followed by 100 mg artemether plus 100 mg doxycycline at 12 hours later, then 100 mg doxycycline every 12 hours for another 4 days, or (b) 300 mg artemether together with 500 mg azithromycin, followed by 250 mg azithromycin at 24 and 48 hours. The follow-up period was 28 days. Patients in either group had a rapid initial response to treatment with comparable PCT and FCT. The cure rate of artemether-azithromycin regimen was significantly lower than that of artemether-doxycycline regimen (14.8 vs 53.3%). Low cure rate from artemether-azithromycin combination in this study was likely to be due to inadequate azithromycin dosage. However, with the low incidence of gastrointestinal adverse effects, the once daily dose of azithromycin could still be increased in order to enhance its clinical efficacy. The simplicity of drug administration and lesser incidence of adverse effects make azithromycin a more proper partner of artemether than doxycycline. Further dose-finding and pharmacokinetic study with the artemether-azithromycin combination is encouraging.