Cavernous sinus thrombosis (CAST) is a rare and potentially fatal complication following tooth extraction. In present case of a 55 year old male known case of diabetes mellitus underwent tooth extraction. After 5 days, he noticed swelling around the cheek, high grade fever, and frontal headaches. Diagnosis of alveolar abscess after inspection was made, for which incision and drainage was done. Next morning, he noticed that the cheek swelling progressed to left eye and there was CT brain was performed which showed hyperdense areas in cavernous sinus on left side and left sylvian fissure with hemorrhagic venous infarct in left temporal and frontal lobes. More caudal sections revealed mucosal thickness in left maxillary and ethmoidal sinuses, edema over cheek, preseptal orbital swelling, retro-orbital fat stranding and axial proptosis. A diagnosis of rhino-orbital infection from dental source with cavernous sinus extension causing left temporo-frontal hemorrhagic venous infarction was made Emergency surgery for decompression was performed but the patient did not responded to the treatment and succumbed to the infection. This case is a reminder that in patients with uncontrolled diabetes, undergoing dental procedures should be carefully dealt with appropriate antibiotic cover. Early signs like unilateral facial edema, orbital chemosis, edema, and proptosis should raise high index suspicion of cavernous sinus thrombosis.