A hematological study was conducted with two species of sea turtles, the green and the loggerhead to evaluate the blood parameters of the turtles during high and low population density periods at Ras Al-Hadd, Sultanate of Oman. Blood samples were taken from healthy individuals during nesting exercise or when they just emerge from the sea. Blood hemoglobin concentration (Hb g/100), packed cell volume (PCV), mean corpuscular hemoglobin concentration (MCHC) and plasma Fe++, were analyzed. There was no significant difference both intra-specifically and inter-specifically in hemoglobin concentration. However, iron values were significantly low in the low-density green turtle while the PCV values were not significantly different when the three groups were compared. Moreover, there were no significant differences in all blood parameters of both species when the blood values were compared between the respected nesting turtles and turtles just emerging from the sea. The stable hematological indices during nesting as well as the close similarities, particularly between high density green turtle and loggerhead may signify that they may have the same physiological response to stress during nesting. In addition, significantly higher values of MCHC of low-density green turtles may indicate erythrocyte swelling.