40 children and adolescents, recurrence of a spondylolisthesis after posterior or even postero-lateral fusion is a well known fact. Anterior fusion added to the posterior graft is said to prevent such and occurrence. We report a case of a L4/L5 listhesis which followed near complete reduction of a 70% L5/S1 slip fixed by a combined approach. We think this is due to the persisting lumbo-sacral postural abnormalities and that while reducing and fixing the spondylolisthesis one should restore physiological posture to prevent this recurrence at the same level or at a higher one.