The aneurysmal bone cyst is an uncommon, locally destructive osteolytic bone lesion occuring mos commonly in long bones. It is relatively rare in the maxillofacial region. Various treatment options have been proposed as conservative or radical surgery. The importance of the lesion in the maxillofacial surgery pactice is that it may easily confuse with malignancy. It is important the close follow-up of the solid aneurysmal bone cysts due to their aggresive behaviour and the affinity to recurrence. This paper presents a rare case of a solid aneurysmal bone cyst (ABC) involving the left corpus mandible in a 15-year-od-girl, with a 2.5 years of follow-up.