The aim of this article is to provide a summary overview of some of the more important scientific evidence of neurological differences between stutterers and non-stutterers. Stuttering is a complex disorder of speech fluency, the aetiology of which is still largely unclear. Although most of the knowledge about stuttering has been derived from clinical observations, essential information obtained through laboratory research delineated some important neurological differences between people with a stuttering problem and people who do not stutter. These differences are identified in terms of neuroimaging, speech production processes and even in terms of auditory perception and feedback mechanisms. The development of new and improved neuroimaging techniques has greatly enhanced the potential to investigate neurological correlates of stuttering. Current knowledge is indicative of a complex neurological basis for stuttering. However, on the basis of current scientific evidence any currently held theory cannot be conclusively substantiated.