Parasitaemia was monitored in vivo on 182 chloroquine-resistant falciparum malaria infections of Gokwe district treated with sulfadoxine/pyrimethamine. Asexual parasitaemia was cleared by day seven in 181 of the 182 patients, while in one, low level parasitaemia persisted beyond day seven post treatment. Late RI recrudescence occurred in five (3 pc) of the infections after initial clearance by day seven. Of the 182 malaria patients, 27 had not taken chloroquine two weeks prior to treatment with sulfadoxine/pyrimethamine (criterion for WHO in vivo drug sensitivity test subjects). Asexual parasite clearance was 100 pc in these patients by day six post treatment (mean time to parasite clearance 2.3 +/- 1.00 days). Recrudescence did not occur in two of the patients followed up on day 14 and in one followed up on day 21. This study showed that sulfadoxine/pyrimethamine was still an efficacious drug at clearing asexual parasitaemia within seven days on chloroquine resistant falciparum malaria in Gokwe district.