Introduction: The purpose of this study was to investigate variations of hematological parameters following two bouts of concurrent endurance-resistance exercises.Material and Methods: Eight physical education students (age 21±1.51 years, height 178±5.57 cm and weight 74.25±8.85 kg) took part in this study. The subjects performed two sessions of concurrent endurance and resistance exercises for 90 minutes in the morning and afternoon evenly. In order to measure hematological variations (WBC, RBC, HCT, HB, MCH, MCHC, MCV, PLT and PV) before, immediately after and 3 h after exercises, the subjects were asked to take fast overnight for 12 h. Blood samples (5cc) were taken from an anticubital vein. The data were analyzed using a 1-factor repeated measure ANOVA and bonferroni post hoc test and the significance level was considered as (P£0.05).Results: According to the obtained data, significant increases in WBC 3 h after exercises and PLT immediately after exercises were observed (P£0.05). Also, there were significant decreases in HCT, HB and RBC variables 3 h after exercises (P£0.05). However, there were no significant differences in MCH, MCHC, MCV and PV (P>0.05).Conclusions: With regard to the decrease in the effective hematological factors in gas exchange and its likely effects on active muscle oxygenate and the increase in the immune factors and coagulation after two exercise sessions, it is suggested that the coaches and athletes take the performance of repeated and concurrent exercises into account.