Belief reasoning plays a central role in making inferences about other people's mental states. The ability to reason about false beliefs is considered as a critical test for having a Theory of Mind (ToM). There is some controversy as to whether it is the medial prefrontal cortex (MPFC) or the temporo-parietal junction (TPJ) that is centrally involved in belief reasoning. According to developmental studies of belief reasoning we conducted an fMRI experiment with a carefully controlled paradigm (Sally Anne scenario). We compared false belief reasoning with true belief reasoning in parallel tasks, using a series of cartoon stories depicting transfer of an object unbeknownst to the protagonist (false belief) or with the protagonist witnessing (true belief). The false belief versus true belief contrast revealed activation of the dorsal part of the anterior cingulate cortex (dACC), the right lateral rostral prefrontal cortex and the right TPJ associated with false belief. We suggest that the activation of the dACC and the lateral PFC might be associated with action monitoring and stimulus-independent cognitive processing whereas the activation of the TPJ might be related to the computation of mental representations that create perspective differences, such as a person's false belief that contrasts with reality and therefore might be centrally involved in the decoupling mechanism. Additionally we found common patterns of activation for true and false belief reasoning, including inferior parietal and precuneus activation, but we found no activation of the MPFC or the TPJ in general belief reasoning.