Cavernous sinus thrombophlebitis is a rare but life-threatening complication of sinus infections, associated with a high mortality rate of approximately 25%, and necessitating prompt diagnosis and aggressive treatment. Our study presents the case of a 78-year-old female who presented with severe headaches, right upper eyelid ptosis, restricted adduction of the right eyeball, and diplopia. Following comprehensive treatment with endoscopic sinus surgery, targeted antibiotics, and anticoagulation therapy, the patient was successfully stabilized and transferred to the internal medicine department in good general condition, with resolution of initial symptoms. This case emphasizes the critical role of advanced imaging techniques, such as magnetic resonance imaging, in achieving an accurate diagnosis, and demonstrates the effectiveness of a multidisciplinary treatment strategy incorporating surgical intervention, antimicrobial therapy, and anticoagulation. It also draws attention to the importance of close clinical monitoring of patients in the postoperative period due to the high possibility of complications. This case adds to the existing literature by illustrating successful treatment approaches and highlighting the importance of personalized care in managing complex clinical scenarios.