Objective:To explore the surgical treatment of lumbar double-level spondylolisis complicated with single-level spondylolisthesis.Method:11 cases with lumbar double-level spondylolisis complicated with single-level spondylolisthesis between August 2000 and November 2007 were reviewed retrospectively.Of these,4 cases had L4,L5 bilateral spondylolisis complicated with L4 spondylolisthesis.4 cases had L4,L5 bilateral spondylolisis complicated with L5 spondylolisthesis.1 case had L3,L4 bilateral spondylolisis complicated with L3 spondylolisthesiss.2 cases had L3,L4 bilateral spondylolisis complicated with L4 spondylolisthesis.All pa-tients underwent posterior decompression,reduction and fusion by pedicle screw instrumentation.Among these protocols,7 cases had interbody,transforaminal and isthmic bony graft,4 cases had transforaminal and isthmic bony graft,while at levels with spondylolisis rather than spondylolisthesis,transforaminal and isthmic bony graft were performed.The surgical outcomes were evaluated according to of the criteria designed by Hou Shuxun et al.Result:The avarage surgical time was 210 minutes (range,180 -260min),with the average intraoperative blood loss of 800ml (range,600 -1200ml).There was no complication such as nerve root injury and cerebrospinal fluid leakage.After a mean follow-up of 18 months (range,8-30 months).Radiography and spiral CT showed thorough reduction in 10 cases,partial reduction in 1 case.Bony fusion was achieved in 10 cases with the fusion period of 7 months(range,5-15 months) with no incidence of hardware failure.Bony fusion was not evidenced until 8 months in 1 case who was lost follow-up finally.At final follow-up,there were 8 excel-lence,2 good and 1 fair.Conclusion:Posterior decompression,reduction and fusion by pedicle screw instrumentation is reliable in dealing with lumbar double-segmental spondylolisis complicated with single segmental spondylolisthesis.