The present study describes hematologic parameters for the Mimus gilvus species in captivity. 45 blood samples of 12 birds (6 male and 6 female) were taken, during four periods with intervals of 21 days, two of them during the rainy season and the other two during the dry season, in order to determine the existing differences depending on the sex variables and the weather conditions. It was established that there are no hematological differences regarding the birds' sex, but it was found that there is a significant difference between the weather periods in the sample media of the indicators: hematocrit, hemoglobin, mean corpuscular hemoglobin concentration, mean corpuscular volume and total platelet count. Neither the difference in the total erythrocyte count was found nor the total leukocyte count showed changes. A significant difference was found in the differential count of leukocytes in these two periods in the basophils and eosinophils media. Reference values are provided for hematological values in this species.