Degenerative lumbar spinal stenosis (DLSS) can be treated by several surgical procedures. However, the choice of procedure and use of instrumentation remain controversial. In this retrospective study of 81 patients with DLSS, 43 patients received decompression and posterolateral fusion without instrumentation, and the surgery for 38 patients was supplemented with posterior transpedicular screw fixation. Both surgeon-based (Fischgrund criteria) and patient-based (Medical Outcome Trust Short-Form 36 [SF-36] questionnaire) standards were used to assess the clinical outcomes. An excellent to good result was achieved in 71.6% of patients and there was no significant difference 6.2 years later between groups with or without instrumentation (Z=0.0358, p>0.05). SF-36 data revealed significant postoperative improvement (p<0.01), and there was no significant difference between the two groups (t=1.67, p>0.05). Successful fusion occurred in 87% of patients with instrumentation versus 67% of the patients without instrumentation (chi(2)=4.23, p<0.05). Thus, surgical treatment of DLSS generally results in satisfactory outcomes. Transpedicular screw fixation may not improve clinical outcomes and the use of posterior instrumentation should be adopted cautiously.