Purpose : This study investigated the diurnal rhythm of cortisol in male and female adolescents. Methods : Salivary cortisol was examined in 52 normally developing subjects aged 13 to 14 years. Subjects provided saliva samples at 08:00h, 12:00h, 16:00h and 20:00h. Results : Males and females showed similar pattern of cortisol, which elevated cortisol in the morning and decreased in the evening. There were no differences of gender at 08:00h, 12;00h and 20:00h. There were also not difference between males and females using an area under the curve analysis. Conclusions : The same diurnal cortisol rhythm were found in male and female adolescents. Further research is needed to examine differences of gender in cortisol awakening response.