In vivo tests for chloroquine sensitivity of P. falciparum malaria parasites were carried out on a sample of 130 patients (mean age, 21 years) from two PHCs during October-November 1988. During this period 20 cases (5.2%) were found positive for all seven days suggesting the presence of RII/RIII chloroquine resistance. All the resistant cases were treated with metakelfin successfully without any recrudescence.