Study design: Case report Setting: Tertiary Government Hospital Subjects, Participants: One patient This is a case of a 26-year-old Filipino male who presented with an eight month history of sudden enophthalmos and hypoglobus on his left eye. Imaging revealed an asymmetric contraction and bony remodeling of the left maxillary sinus with concave deformity changes of the left orbital floor, as well as retraction of the left eye globe into the orbital fossa. He was diagnosed as Chronic Maxillary Atelectasis Stage III or Silent Sinus Syndrome. He was surgically managed through an endoscopic middle meatal antrostomy, with left concha bullosectomy. Intraoperatively, a contracted maxillary antrum with a polypoid roof and thick mucoid discharge was visualized. The patient tolerated the procedure well and postoperatively had no complications, with an improvement in his enophthalmos and hypoglobus symptoms. Silent Sinus Syndrome is a condition wherein there is a collapsed maxillary antrum, affecting the orbital floor resulting in enophthalmos but without any sinonasal symptoms. The syndrome’s definition, clinical presentation, diagnostic approaches, and treatment modalities were discussed.