Forty-one patients with herniated lumbar discs in a lateral location underwent unilateral complete facetectomy for removal of their disc herniation. The diagnosis was made by computerized tomography in all patients. The follow-up period varied between 4 and 60 months, with an average of 22.4 months. All patients underwent dynamic lumbar spine x-ray films with flexion and extension exposures at various times during their follow-up period. The results were excellent in 35 patients, good in three, and poor in three. One patient suffered spinal instability postoperatively and required lumbar fusion because of back pain. Unilateral facetectomy gives an excellent view of the affected nerve root and the herniated disc, and the risk of spinal instability is very low.