The purpose of this research was to study growth hormone (GH) response to a session of maximal exercise in active adolescents. For this purpose, 15 subjects (8 females: age 13± 0.5 yrs, height 153.25± 3.73 cm, weight 43± 5.10 kg and 7 males: age 14± 0.5 yrs, height 166.86± 6.07 cm, weight 52.86± 5.61 kg) performed an incremental exercise protocol on a treadmill with an increasing grade until volitional exhaustion. Blood samples were collected from venous blood of the subjects before and immediately after the exercise. T-test and Pearson correlation were used to analyze the data. The results showed a significant increase in serum GH concentration after exercise in both boys and girls (P<0.05). Also, no significant difference was found before exercise in both groups (1.99 vs. 1.12 ng/ml; P>0.05). But GH response was significantly higher in girls than boys (12.39 ng/ml, 4.23 ng/ml respectively). Regression analysis revealed no significant correlation between BMI and GH responses before exercise in girls and boys. Results from the present investigation indicated an increase in GH concentration after exercise and that women had greater GH release.