Ameloblastoma is the 2nd most common odontogenic tumor following odontoma. The tumor is often asymptomatic and commonly seen in mandible but it may also develop in maxilla. Unicystic ameloblastoma clinically and radiographically presents a similar and confusing picture as of Dentigerous cyst when it is associated with tooth. Histopathological examination is essential to diagnose such cases. We report a case of young male with a radiolucent lesion in left maxilla associated with impacted 3rd molar. Surgical removal of lesion was performed, with differential diagnosis of dentigerous cyst. However, histopathological examination reveled ameloblastoma over dentigerous cyst.