A unhealthy 58-year-old male patient required extraction of left upper second molar due to advanced periodontitis. Lidocaine contained 1 : 100000 epinephrine for left posterior superior alveolar nerve block was administered in the mucobuccal fold above the second molar to be treated at the local private dental clinic. After four hours of posterior superior alveolar block anesthesia, patient feeled double vision and discomfort of eyeball movement. At next day, he complained difficulty of left eyeball movement, vertigo and diplopia. He was referred to our department via local clinic and department of ophthalomology of our hospital. He was treated by medication and eyeball exercise, and then follow up check. The double vision and medial rectus muscle palsy disappeared patially after 2 months of block anesthesia. We described herein an ocular complication of diplopia and inferior rectus muscle palsy after posterior superior alveolar nerve block for extraction of left upper second molar, and review the cause or origin of this case. The autonomic nervous system is presented as the logical basis for the untoward systems of ophthalmologic sign likely to diplopia and inferior rectus muscle palsy, rather then simple circulation of anesthetic solution in the vascular network.