The present study investigated whether the human mirror-neuron system exhibits gender differences. Neuromagenetic mu (∼20 Hz) oscillations were recorded over the right primary motor cortex, which reflect the mirror neuron activity, in 10 female and 10 male participants while they observed the videotaped hand actions and moving dot. In accordance with previous studies, all participants had mu suppression during the observation of hand action, indicating activation of primary motor cortex. Interestingly, the female participants displayed apparently stronger (P<0.05) suppression for the hand action than for the moving dot whereas the men showed the opposite (P<0.05). These findings have implications for the extreme male brain theory of autism and support the hypothesis of a dysfunctional mirror-neuron system in autism.