Hemifacial spasm is a syndrome of unilateral facial twitching characterized by frequent, involuntary facial muscle contractions, resulting in impaired quality of life. Since Jannetta first made serendipitous microsurgical observation on microvascular decompression in 1966, the knowledge of hemifacial spasm has increased with advances in neurophysiological technique, diagnostic imaging and surgical experiences. Vascular pulsatile compression on the root exit zone of the facial nerve causes this phenomenon and surgical decompression of the offending vessel has therefore been established as a curative treatment for hemifacial spasm.