Aims: To clarify correlation between magnetic resonance imaging (MRI) and pathology of pain in posterior aspect of the ankle in ballet dancers. Methods: Twenty feet of þfteen patients, who underwent surgery with the average age of 19.2 years, were retrospectively analyzed. They were diagnosed as ßexor hallucis longus (FHL) tendon injury or posterior ankle impingement (PAI) syndrome mainly based on physical signs. MRI þndings of FHL tendon were classiþed with the classiþcation of posterior tibial tendon dysfunction presented by Conti et al., and were compared with macroscopic changes of the tendon. FHL injuries were classiþed as follows; paratendinitis as grade-1, superþcial injury (< 1/2 thickness) as grade-2, and deep injury as grade-3. MRI þndings of PAI syndrome were also compared to surgical and histological þndings. Results: Correlation of FHL tendon injury with MRI þndings was presented on the table. There was a case with a ganglion cyst of FHL tendon presented on MRI. There were, however, two cases with ganglions on þbro-osseous tunnel MRI could not reveal. In four feet of three patients, bone marrow edema in os trigonum or posterior part of the talus was observed. Conclusion: MRI was useful to investigate the pathology of pain in posterior aspect of the ankle.