In March 1993, a study was undertaken in the Komatipoort/Malelane area to monitor the in vitro sensitivity of Plasmodium falciparum to antimalarial drugs currently in use in South Africa. Of the 12 isolates collected, 7 were successfully tested for sensitivity to chloroquine and quinine, 6 for mefloquine susceptibility, and 5 for sensitivity to Fansidar. Four of the isolates were resistant to chloroquine at RIII level, 1 at RII level, and 2 were sensitive. All isolates were found to be sensitive to both quinine and mefloquine. Results suggested possible resistance to Fansidar. These findings have implications for tourists travelling to this area.