The question whether human beings have free will has been debated by philosophers and theologians for thousands of years. More recently, neuroscientists have applied novel concepts and tools in neuroscience to address this question. We submit that human beings do have free will and the physiological substrate for its exercise is contained within neural networks. We discuss the potential neurobiology of free will by exploring volitionally initiated motor activity and the behavioural-response to a stimulus-response paradigm. We also submit that the (...) exercise of free will can be affected in patients with the certain neurological disorders such as the behavioural variant of frontotemporal dementia. Clinicopathological correlation in patients with this disorder provides an opportunity to further elucidate the neural substrate for this fundamental human attribute. We also discuss the clinical correlates of the loss of free will in this population, which is a source of significant distress to patients, significant others and care givers. (shrink)