Persons with autism spectrum disorder (ASD) show atypical engagement in imitative interaction with peers and caregivers. Because imitative interaction is a precursor of a theory of mind, disturbances of the brain regions associated with imitative interaction are an important component of the pathophysiology of ASD. Recently, advanced functional magnetic resonance imaging (fMRI) studies have begun to address the neural basis of reciprocal imitation in individuals with ASD, which includes both imitating another’s action and being imitated by another person. These studies suggest that a disturbance of an internal model represented by the human mirror neuron system (MNS) leads to atypical engagement in imitative interaction. However, it is still unknown whether individuals with ASD have an abnormality in the MNS itself or altered modulation/control of the MNS. We also discuss how to resolve this question and the possibilities of a new fMRI technique, hyper-scanning, for understanding the neural underpinnings of atypical engagement in imitative interaction.