Facial emotion perception is fundamental to human social behaviour, and changes with age. Nevertheless, age-related differences in the relative activation of components of emotion processing networks are poorly understood. Thus we measured brain activity with event-related fMRI in 40 right handed healthy male controls, age range 8-50 years, during implicit processing of fearful, disgusted, and a control condition of neutral facial expressions. There was a significant negative correlation between increasing age and neural response to fearful and disgusted expressions in dorsomedial prefrontal cortex (BA 10), and middle frontal gyri (BA 6). Hence, in healthy subjects, the functional anatomy of facial emotion processing is not 'hard-wired', but undergoes progressive change into adulthood. Possible explanations for the age-related changes in dorsomedial and middle frontal cortical activity may include a reduction in the attentional demands of appraising facial expressions as perceptual skill increases, or changes in processing the self-relevance of facial expressions during social and cognitive development.