Knowledge about the aetiology of Gilles de la Tourette syndrome (GTS) is very limited. GTS has a complex mode of inheritance in which both genetic and environmental factors are believed to be involved in disease development. Different approaches to identify GTS associated genes have led to the discovery of several candidate genes. However, none of these has been shown to be major causative genes associated with the development of GTS. Future use of large clinical cohorts and new technologies will hopefully result in the identification of genes associated with GTS.