Human choices are not only driven by inner preferences, but also have an impact on behavior. Economists and psychologists have extensively demonstrated that choosing between two attractive options leads to a downgrade of the rejected option and to an upgrade of the chosen one. Preference modulation after the mere act of making a choice has been repeatedly demonstrated over the last 50 years by an experimental paradigm called the ‘free-choice paradigm’. In the past decade the phenomenon of choice-induced preference change generated by cognitive dissonance has been explored by neuroscientists. An increasing amount of research has highlighted the central role of the posterior medial frontal cortex (pMFC) in social conformity and cognitive dissonance. This area represents the dissonance between one’s currently inconsistent and ideally consistent states. However, other brain areas have been linked to cognitive dissonance and its resolution, but as yet the mechanisms underpinning cognitive dissonance and the functional connection among brain areas found involved in cognitive dissonance are still unknown. Here, we firstly review the neural mechanisms and brain areas involved in post-decisional preference change and cognitive dissonance. Secondly, we suggest an integration of the existing neurocognitive mechanism of cognitive dissonance. Finally, we suggest new research lines to further explore neural principles of cognitive dissonance and subsequent post-decisional preference change.