One hundred two patients aged 2-43 years diagnosed with acute malaria due to P. falciparum or P. vivax were treated with 3 doses of halofantrine (500 mg for > or = 18 year old patients and 8 mg/kg of patient body weight for 2-17 year olds), with each dose administered once in 6 hours and followed up for 28 days. Out of 102 patients 63 had P. falciparum, 36 had P. vivax and 3 had unidentified species. Following three dose therapy, 96.1% (98/102) of patients were cured, 0.98% (1/102) showed improvement from baseline, 1.96% (2/102) did not respond and were considered as treatment failures and one patient had indeterminate data. The lone patient, who relapsed after 120 hours post dose 1, was cured following re-treatment on day 7. The median parasite clearance and fever clearance times, from the first dose, were 26 hours and 30 hours, respectively. Eleven point eight percent (12/102) of patients reported adverse events, of which abdominal pain, reported by one subject, was considered to be probably related to the drug and required corrective therapy. There were no serious adverse events or fatalities and none of the patients had a change in QTc interval greater than 10%. Thirteen point seven percent (14/102) of patients had abnormal clinical laboratory parameters that normalized later.