In order to evaluate the hemogram values and the morphological characteristics of blood cells in Olive Ridley turtle, from 22 physically healthy marine turtles Lepidochelys olivacea living in the wild at the beach in Barra de La Cruz, Municipality of Santiago Astata in the State of Oaxaca, Mexico. The sampling was obtained during spawning, and hemogram was performed on each one, from which the following results were obtained: hematocrit (0.30 +/- 0.04 L/L), total protein (47.14 +/- 5.85 g/L), mean corpuscular volume (MCV) (891.79 +/- 291.93 fL), total erythrocytes (0.37 +/- 0.12 x 10(12)/L), total leukocytes (4.51 +/- 3.03 x 10(9)/L), differential leukocyte count: heterophils 2.87 +/- 1.88 x 10(9)/L, eosinophils 0.89 +/- 0.68 x 10(9)/L, basophils 0.08 x 10(9)/L, lymphocytes 0.64 +/- 0.59 x 10(9)/L, and the estimate of the number of thrombocytes (127 +/- 47). The main morphological characteristics were also described: size, shape, and color; scarce morphological differences of the blood cells in contrast to other marine turtle specimens were detected.