Our knowledge on the development of the affective and cognitive circuitries that underlie affect regulation is still limited. This functional magnetic resonance imaging (fMRI) study examined whether there is more efficient prefrontal modulation of affective circuits with development. Ten adolescents (mean age 14 +/- 2 years) and 10 adults (mean age 30 +/- 6 years) underwent two scanning conditions that required different levels of cognitive control over face emotion processing. A 'directed' emotion processing condition required judgment of facial expressions. An 'incidental' emotion processing condition required an age judgment. For the incidental emotion processing condition, adolescents, compared with adults, showed less activation in right ventrolateral prefrontal cortex (VLPFC) and greater activation in paralimbic regions, suggesting greater emotional reactivity and immature prefrontal circuitries for affect regulation. For the directed emotion processing condition, adolescents, compared with adults, showed decreased recruitment of both the dorsal and pregenual right anterior cingulate cortex (ACC), suggesting immature modulatory functions of the ACC during directed face emotion processing. These results indicate that the neural circuitries for affect regulation are still developing in adolescence and have not yet reached the adult level.