Distal femoral cortical irregularity (DFCI) is a benign entity presenting with either an irregular appearance or a focal radiolucency within the posterior cortex of the distal femur. Atypical cases should be differentiated from malignant lesions. The typical location of the lesion at the attachment of the head of the medial gastrocnemius muscle can be visualised using different imaging techniques. We report a case of a DFCI in a 13-year old boy. The diagnosis was based on CT-imaging. Two years later, no radiological abnormalities could be observed. A review of the literature is presented.