Bruxism, the rhythmic grinding of teeth--usually during sleep--is not an infrequent complication of traumatic brain injury. Its prevalence in the general population is 21%, but its incidence after brain injury is unknown. Untreated, bruxism causes masseter hypertrophy, headache, temporomandibular joint destruction, and total dental wear. We report a case of complete resolution of postanoxic bruxism after treatment with botulinum toxin-A (BTX-A). The patient was a 28-year-old man with no history of bruxism who sustained an anoxic brain injury secondary to cardiac arrest of unknown etiology. On admission to our rehabilitation unit 2 months after the injury, the patient presented with severe bruxism and heavy dental wear. The patient was injected with a total of 200 units of BTX-A to each masseter and temporalis. There was total resolution of bruxism 2 days after injection, with no complications. On follow-up 3 months after injection, the patient remained free of bruxism. We propose that botulinum toxin be considered as a treatment for bruxism secondary to anoxic brain injury. Further studies regarding muscle selection and medication dosage are warranted to elucidate the toxin's efficacy in this condition.