Objective To evaluate the efficacy of posterior approach discectomy with and without fusion in the treatment of lumbar disc herniation. Methods We searched MEDLINE (1950 to June 2007), OVID (1950 to April 2007), PUBMED, the China Biological Medicine Database (1978 to June 2007) and Wanfang Database (1981 to February 2007). We also handsearched several relevant journals for randomized controlled trials (RCTs) and quasi-randomized controlled trials (quasi-RCTs) comparing posterior approach discectomy with and without fusion in the treatment of lumbar disc herniation. The quality of the included trials was assessed. The Cochrane Collaboration’s RevMan 4.2.8 software was used for statistical analysis. Results Nine eligible trials involving 1911 patients were included. The meta-analyses found no statistically significant differences between the two operative procedures in the incidence of postoperative leg pain [RR 0.94, 95%CI (0.69, 1.28)], the proportion of patients requiring re-operation [RR 0.77, 95% CI (0.57, 1.04)], the incidence of post-operative lumbar canal stenosis [RR 1.23, 95%CI (0.26, 5.86)], and the relapse rate at other intervertebral spaces [RR 1.05, 95%CI (0.49, 2.26)] (Pgt;0.05).There is statistically significant differences between the two group in the incidence of peri-operative complications [RR 1.46, 95%CI (1.06, 2.00)]. Discectomy plus fusion was superior to discectomy alone in incidence of postoperative back pain [RR 0.70, 95%CI (0.53, 0.94)], relapse rate at either intervertebral space [RR 0.30, 95%CI (0.18, 0.48)] and at the same intervertebral space [RR 0.12, 95%CI (0.04, 0.37)]. Conclusions Since all the included studies were controlled trials with a great potential for biases, high-quality, large-scale randomized controlled trials are required.