Desmoplastic fibroma (DF) of the bone, also know as desmoid tumour, is a rare non-metastasizing but locally aggressive tumour. In this case report, we present imaging findings of a histopathologically proven desmoplastic fibroma involving the left mandibular region in a 15-year-old Chinese patient. We have also discussed the usefulness of different imaging modalities (plain film radiography, CT and MRI) in DF diagnosis and treatment.