The purpose of this study was to investigate the hematological parameters after incremental maximal exercise in sixteen male subjects; eight with chronic hepatitis (20.88 ± 1.73 years; CH) and eight of normal health (21.50 ± 0.93 years; Control group). All of the subjects performed exercise on a treadmill to the point of exhaustion. Total white blood cells (WBC), lymphocytes (L), total red blood cells (RBC), hemoglobin (Hb), hematocrit (Hct), and platelet (P) responses were measured in this study. Blood samples were drawn from the subjects previous to their beginning of the exercise (Tl) and subsequently five minutes (T2), three hours (T3), twenty-four, hours (T4), and forty-eight hours (T5) after completion of the exercise. The results showed that while there was no significant difference between the CH group and the C group before the exercise, after completing the exercise, all hematological values except P were significantly higher at the T2 measuring point than at Tl, in both the CH group and the C group. In the WBC levels, there was a than at Tl – in both the CH group and the C group. In the WBC levels, there was a significant difference at T2 between the CH group and the C group (11675 ± 3788vs; 8825 ± 2522 mm-3; p＜0.5).Also, almost all parameters returned to pre-exercise levels at T3 except for L, where it returned to below pre-exercise level. In addition, there were significant differences between the value at the T1 and T3 measuring points in both the CH group (36.50 ± 5.90vs; 24.13 ± 8.36%; p＜.05) and the C group (34.50 ± 7.09vs; 20.38 ± 6.23%; p＜.5). There were no slgnificant changes in any of the other parameters investigatd on this study. The conclusion of this study is that acute incremental maximal exercise will induce an increase in hematological parameters in chronic hepatitis patients and normal individuals. Patients with chronic hepatitis show more negative exercise induced immunological responses than normal individuals.