Deception, also known as "lying", is a pervasive and fundamental social behavior in which a person attempts to persuade another to accept as true what the deceiver believes to be untrue. Because of its essential role in our social life, it is important for social neuroscience to reveal the inner workings of deception. This special issue provides a representative sample of new empirical research on the cognitive and neural processes associated with producing deceptive responses. Eight contributions report studies employing a variety of paradigms and techniques (behavioral, functional magnetic resonance imaging, event-related potentials, and transcranial magnetic stimulation) that address several theoretical and methodological issues for deception research. Numerous questions are raised by these studies. First, is deception a unitary phenomenon, and are all lies the same? If there are different types of lies and there are individual differences in deception, can lies be detected reliably in single individuals? Second, are deception processes special in any way or do they depend only on a set of general-purpose cognitive and neural processes? Third, is it valid to study deception in the laboratory, and to what extent can laboratory studies be designed to resemble real-life deception situations? Fourth, are different cognitive and neural measures associated with deception affected equally by different factors? Can we devise reliable methods to detect deception by exploiting this knowledge? These questions provide important directions for future research. Establishing the brain correlates of deception behaviour will be challenging, but already we have made great strides.