The aim of this study was characterized the blood cells and quantified the blood thrombocytes and leukocytes of juveniles Salminus brasiliensis maintained in experimental conditions of culture, since fingerling culture. Thirty-five health specimens were used for total thrombocytes and leukocyte counts, and differential leukocytes counts. The blood cells were identified as: erythrocytes, neutrophils, heterophils, eosinophils, monocytes, lymphocytes, immature leukocytes and thrombocytes. The average values of leukocytes and thrombocytes were: thrombocytes 18,820.75 ± 7,067.64 .μL-1, total leucocytes 21.072,93 ± 7.867,62 .μL-1, monocytes 509.73 ± 363.01 .μL-1, lymphocytes 18,312.21 ± 6,977.27 .μL-1, heterophils 247.20 ± 497.69 .μL-1, eosinophils 450.89 ± 423.89 .μL-1, neutrophils 1,165.42 ± 937.75 .μL-1 and immature leukocytes 392.58 ± 344.67 .μ
