The ability to understand the goals and intentions behind other people's actions is central to many social interactions. Given the profound social difficulties seen in autism, we might expect goal understanding to be impaired in these individuals. Two influential theories, the "broken mirror" theory and the mentalising theory, can both predict this result. However, a review of the current data provides little empirical support for goal understanding difficulties; several studies demonstrate normal performance by autistic children on tasks requiring the understanding of goals or intentions. I suggest that this conclusion forces us to reject the basic broken mirror theory and to re-evaluate the breadth of the mentalising theory. More subtle theories which distinguish between different types of mirroring and different types of mentalising may be able to account for the present data, and further research is required to test and refine these theories.