Conclusions. Long-term clinical and radiographic outcomes after posterolateral fusion of low-grade spondylolisthesis were satisfactory. Cosmetic aspects of this deformity should be included as one of the outcome measurements, since cosmetic questions on the Scoliosis Research Society questionnaire showed inverse correlations between the amount of slip at final follow-up observation. The Scoliosis Research Society questionnaire could be used as a primary patient-oriented outcome tool after back surgery in young patients.