Aim:Although many studies have compared lateral interbody fusion (direct [DLIF] or oblique [OLIF] lumbar interbody fusion) and posterior interbody fusion (posterior [PLIF] or transforaminal [TLIF] lumbar interbody fusion) for the lumbar spine, there exist a patient selection bias with heterogeneity in indications or symptoms. In this study, we compared lateral and posterior interbody fusion results in patients with the same indication of discogenic low back pain. Material and Methods:We enrolled 46 patients who underwent single-level DLIF/OLIF or PLIF/TLIF with at least 1 year of follow-up. Patients were divided into two groups: a lateral group (n=24) who underwent DLIF/OLIF and a posterior group (n=22) who underwent PLIF/TLIF. Clinical, surgical, and radiological outcomes were retrospectively evaluated. Results:Baseline factors, including demographic data, preoperative symptoms, and preoperative radiological findings, were not significantly different between the two groups. In addition, the clinical and radiological outcomes at 1-year post-surgery did not differ between the two groups. However, the DLIF/OLIF procedure conferred significant advantages as follows: favorable postoperative low back pain and patient satisfaction at 1-week and 1-month post-surgery; shorter operation time (mean 173.33±11.54 versus 208.64±17.48 min, p<0.001); less blood loss during surgery (mean 127.50±41.36 versus 372.73±123.21 mL, p<0.001); and greater restoration of calibrated disc height at 1-year post-surgery (mean 5.80±1.44 versus 0.50±1.22, p=0.008). There was no statistically significant difference in the incidence of complications between the two groups. However, complications tended to be more frequent in the lateral group; 7 (29.2%) patients in the lateral group and 3 patients (13.6%) in the posterior group.Conclusion:Our findings suggest that the lateral group achieved better perioperative outcomes and disc height restoration than the posterior group, although there was no significant difference in the 1-year clinical outcomes.