Cemento-ossifying fibroma (COF) is a rare nonodontogenic tumor of the periodontal membrane that arises from the mesodermal germ layer. Clinically, these lesions are usually asymptomatic, slowly growing, and well circumscribed. However, they have demonstrated an aggressive course of development in a very small number of cases, particularly in younger patients. Surgical management via wide local excision is necessary because COF is notorious for recurrence, particularly lesions in the paranasal sinuses. We describe a case of juvenile aggressive COF of the sinonasal tract in a 12-year-old boy. This tumor presented with various overlapping clinical, radiologic, and pathologic features, which led to initial confusion and a diagnostic dilemma. We also discuss the radiologic interpretation of COF, which can be helpful in making the diagnosis and in selecting the appropriate surgical approach in a growing child.