ACKGROUND: Dentigerous, follicular, cysts are developmental odontogenic cysts of reduced adamantine epithelium origin, associated with an impacted tooth. They are the second most frequent cystic pathology after inflammatory cysts. Although the frequency of dentigerous cysts associated with upper third molars is far lower than the mandibular ones, their complications are nothing but ordinary. Most of the times asymptomatic, being discovered during routine x-ray examinations, maxillary follicular cysts can grow to important size, altering the position of adjacent teeth, producing osteolysis of the nearby bone structures, as well as infectious complications, antral and orbital pathology. CASE REPORT: The present manuscript describes the clinical, radiological, pathological and therapeutical aspects of a giant follicular cyst with antral and pterygomaxillary extension, associated with an impacted upper third molar. CONCLUSION: The most efficient treatment of maxillary follicular cysts consists in the surgical removal of the lesion along with the involved tooth. Complete excision is mandatory to prevent recurrence. Extension into adjacent structures might complicate the surgery Preoperative evaluation and rigorous planning are essential, especially in large-sized lesions. Pathological examination is outmost importance in order to exclude aggressive transformations