Classification of ameloblastomas into solid or multicystic, unicystic, peripheral and desmoplastic types based on the biological behaviour has gained recent recognition in the new WHO classification of head and neck tumours. The distinctive clinical and pathological features of the unicystic variant were reviewed. The variability of histological spectrum, diagnostic problems and choice of treatment for this subtype of ameloblastoma were discussed in the light of recent research interest and progress. Keywords: ameloblastoma, odontogenic tumour, unicystic variant