Objective To analyze complications associated with posterior lumbar interbody fusion (PLIF) in which two Bagby and Kuslich (BAK) interbody fusion cages were implanted.Methods A total of 118 patients with spondylolytic spondylolisthesis underwent single-level PLIF using two BAK cages filled with morselized autogenous bone. The major clinical and radiographic complications were analyzed after a follow-up with an average time of 2 years and 9 months.Results Complications were divided into intraoperative and postoperative complications. Intraoperative complications mainly included dural tear (4 patients, 3.4%), nerve root injury (3 patients, 2.5%) and suboptimal cage position (9 patients, 7.5%). No death was caused by the operation. Postoperative complications chiefly consisted of cage retropulsion (3 patients, 2.5%), cage subsidence (4 patients, 3.4%), and postlaminectomy arachnoiditis (2 patients, 1.7%). Pseudarthrosis was noted radiographically with evidence of motion between adjacent vertebra on lateral flexion-extension films and luciencies around the cages (2 patient, 1.7%), continuous posterior cage migration (2 patients, 1.7%) or continuous cage subsidence (2 patients, 1.7%). Two patients died, one from a traffic accident and the other from metastatic cancer 1 year postoperatively.Conclusions The results of this study indicate that PLIF with BAK cages is an effective but also technically difficult procedure. The relatively high incidence of complications reminds us of the importance of surgical indications and proper manipulations.