Phantom limb syndrome is a condition in which patients experience sensations, whether painful or otherwise, in a limb that does not exist. It has been reported to occur in 80-100% of amputees, and typically has a chronic course, often resistant to treatment. Risk factors include the presence of preoperative pain, traumatic amputation, and the type of anesthetic procedure used during amputation. Several pathophysiologic theories have been proposed, including spinal mechanisms, central sensitization, and somatosensory cortical rearrangements, and while recent studies have shed light on some interesting and significant data, a lot remains to be understood. Treatments include pharmacologic, mechanical, and behavioral modalities, but substantial efficacy in well-designed, randomized controlled trials has yet to be demonstrated. Phantom limb syndrome continues to be a difficult condition to both understand and treat.