The common disorder called facet syndrome exhibits back pain, with or without referred or radiating pain due to facet joint arthropathy. Facet joint injection using local anesthetics is a reliable method for the diagnosis and treatment for facet syndrome. Because the complications secondary to facet block have usually been temporary and infrequent, facet block has been known as a simple and safe procedure. But spinal anesthesia is a serious complication of facet block and can lead to a life threatening conditions. The authors report a patient who developed un-explainable cardiac arrest following facet joint injection. A 64 year-old woman with 4-year history of cervical facet syndrome was admitted for the fourth facet block. Cardiac arrest followed with unconsciousness and apnea occurred 4 minutes after cervical facet joint injection with 2 ml of 2% lidocaine. The patient was immediately resuscitated and recovered without any sequelae. Sudden cardiac arrest can be unexpectedly developed during facet block, and we recommend close monitoring during cervical facet joint block.