Eighty-two adolescent patients with symptomatic spondylolysis or spondylolisthesis were treated by nonoperative modalities. Patients' ages ranged from 6.5 to 21 years, and follow-up ranged from 1 to 14.3 years. Thirty-one patients became asymptomatic, 17 had significant but incomplete relief of pain, nine had no relief, and 25 required surgical treatment for pain. Of 12 patients with grade 3 or 4 slip, only one had significant relief of pain, whereas 48 of 70 patients with lesser degrees of slip had significant relief of pain. Nonoperative treatment of degrees of spondylolisthesis of less than or equal to grade 2 can reliably relieve pain in two-thirds of patients.