Dance is a high performance athletic activity that leads to great numbers of injuries, particularly in the ankle region. One reason for this is the extreme range of ankle motion required of dancers, especially females in classical ballet where the en pointe and demi-pointe positions are common. These positions of maximal plantar flexion produce excessive force on the posterior ankle and may result in impingement, pain, and disability. Os trigonum and protruding lateral talar process are two common and well-documented morphological variations associated with posterior ankle impingement in ballet dancers. Other less well-known conditions, of both bony and soft tissue origins, can also elicit symptoms. This article reviews the anatomical causes of posterior ankle impingement that commonly affect ballet dancers with a view to equipping healthcare professionals for improved effectiveness in diagnosing and treating this pathology in a unique type of athlete. Clin. Anat. 23:613-621, 2010. (c) 2010 Wiley-Liss, Inc.