In this study, our aim was to investigate gender effects on prefrontal cortex oxygenation. Auditory oddball paradigm used as cognitive task. Prefrontal cortex oxygenation is assessed by monitoring changes in blood oxygenation using functional nearinfrared spectroscopy (fNIRS). The fNIRS were recorded during the 'oddball' paradigm in which two stimuli (target and standard) were presented in random order. Subjects were asked to press a button in response to the target stimulus. 12 male healthy children and 9 female healthy children were included the study. As a result; it is observed that the males exhibited higher prefrontal activation during auditory oddball task than females. This results suggest that gender had an effect on prefrontal cortex oxygenation therefore gender matching is important for studies of brain function using fNIRS.