The description of amphibian hematology is scarce and most of these studies have been done in species from North America, Asia and Europe. With the purpose to obtain basic hematological information of Rhinella fernandezae, 23 blood samples from Santa Fe and Entre Rios natural reserves were studied. Blood of each individual was extracted by cardiac puncture and hemograms were carried out. Morphological and cytochemical description of blood cells were analyzed in slides and were inspected for extra and intra cellular parasites. Five leucocytes types were observed, being lymphocytes the predominant ones followed by basophiles. Heterophils and eosinophils were positive to PAS, Sudan B and peroxidase. The erythrocytes and its precursors were negative for cytochemical reactions. Micronuclei and nuclear alterations frequencies were scarce. No significant differences (p > 0.05) were observed between sexes neither in hemograms nor in blood cells morphology. Microfilarias were the only hemoparasites found with a relative low prevalence and infection intensity. The hematological characteristics studied were similar to those reported for other amphibians, suggesting that R. fernandezae individuals present optimal nutritional and immunological status.