There has been an increasing interest in the role of personality factors in the outcome of medical treatment. The present study examined the role of personality measures in predicting the outcome of neurosurgery for patients with a well-documented disruption of one or more discs. Each of 15 male and 16 female patients whose average age was 40.8 yr. received the Minnesota Multiphasic Personality Inventory before surgery and received a follow-up at least one year after surgery or until a final, stable level of recovery was attained. A multiple correlation of .64 between the personality measures and treatment outcome suggested that even in cases with a well-documented need for surgery, psychological factors can play a major influence in the eventual outcome. Possible psychological interventions before surgery which might increase the likelihood of a good outcome are briefly outlined.