There is no convincing medical evidence to support the routine use of lumbar fusion at the time of a primary lumbar disc excision. There is conflicting Class III medical evidence regarding the potential benefit of the addition of fusion in this circumstance. Therefore, the definite increase in cost and complications associated with the use of fusion are not justified. Patients with preoperative lumbar instability may benefit from fusion at the time of lumbar discectomy; however, the incidence of such instability appears to be very low (< 5%) in the general lumbar disc herniation population. Patients who suffer from chronic low-back pain, or are heavy laborers or athletes with axial low-back pain, in addition to radicular symptoms may also be candidates for fusion at the time of lumbar disc excision. Patients with a recurrent disc herniation have been treated successfully with both reoperative discectomy and reoperative discectomy combined with fusion. In patients with a recurrent lumbar disc herniation with associated spinal deformity, instability, or associated chronic low-back pain, consideration of fusion in addition to reoperative discectomy is recommended.