The aim of this study was comparatively to evaluate the malaricide activity of the quercetin to the action of the chloroquine in Gallus gallus experimentally infected for Plasmodium juxtanucleare and immunocompromised. Thirty- four hens had been used, previously infected for P. juxtanucleare and immunocompromised by the administration of 26 mg/kg of metilprednisolon 40mg/ml in the pectoral muscle. These had been divided in three groups: 1- control, 2- treated with chloroquine and 3- with quercetin. The administration of substances occurred way gavagem to four consecutive days. The malaricide action of the drugs was evaluated in agreement the parasitemia for P. juxtanucleare in blood smears, during 30 days after the infection. The groups that had received treatment with chloroquine and quercetin had presented significant reduction (p < 0,01 in both) of the parasitaemia comparative to the group control, it suggesting that the drugs had acted as malaricide in the infection for P. juxtanucleare.