Retrospective, descriptive and analytical study of 34 patients, women 18, men 16; average age 50.8 years, with diagnosis of degenerative and isthmic spondylolisthesis (with degenerative component), Treated surgically with transpedicular fixation (FT) + arthrodesis Posterolateral (APL), in the Department of Neurosurgery of the Guillermo Almenara National Hospital between January 1966 and December 2004. The preoperative symptomatology was lumbar pain, neurogenic claudication and root pain. The predominant lesion level was L4-L5 and L5-S1. The degree of listesis Was: I: 6, II: 26 and III: 2. The reduction of the listesis was: total 18, partial 14 and non-reduction 2. The postoperative was with total or partial remission of low back pain in 31 (91%), total remission of neurogenic claudication and root pain in 30 (100%). The Oswestry Scale (functional disability) average: preoperative 64% and postoperative 24%, showed a significant difference (p <0.05). The persistence of residual low back pain mild in 25 (73%) was not associated with the degree of reduction of the listesis (p> 0.05). This results Demonstrate that FTP associated with APL optimizes the results of symptomatic spondylolisthesis surgery of adults with a progressive neurological condition that does not improve with conservative treatment.