Purpose: The purpose of the study was to investigate five cases with chronic Achilles tendon rupture that occurred after steroid injections. Materials and Methods: In our hospital, we experienced five cases of chronic Achilles tendon rupture from September 2010 to March 2012. All patients had got steroid injection for Achilles tendinitis at the other hospitals, and their heel pain was aggravated when they visited our outpatient department. After treatment, signs and symptoms of Achilles tendon rupture were developed and the diagnosis was confirmed by ultrasonography or magnetic resonance imaging (MRI). Surgical treatment was done for Achilles tendon rupture. Results: There was difference between intra-operative findings of Achilles tendon rupture and usual chronic Achilles tendon rupture. Unlike usual findings of chronic Achilles tendon rupture whose scar tissue or tissue attenuation are found around the defect area of Achilles tendon, there were partial necrosis of tendon severe adhesion with surrounding tissue, extensive defect and longitudinal rupture on ruptured area. Also, severe inflammation of paratenon, granulation and fibrinoid deposit were found on biopsy findings in four cases. Conclusion: Based on review of data about relative risk and benefit of local corticosteroid injection to inflammatory lesion in Achilles tendon, it requires more attention to Achilles tendon rupture following local corticosteroid injection.