[Objective]To compare the clinical outcomes of endoscopic versus open bone grafting and pedicle screw fixation for lumbar isthmic spondylolysis in the youth.[Methods]A retrospective study was conducted on 22 patients who received surgical treatment for lum-bar isthmic spondylolysis in our department from June 2017 to January 2021.According to the preoperative doctor-patient communication,12 patients underwent the endoscopic surgery,while other 10 patients underwent the open surgery.The clinical and imaging consequences of the two groups were compared.[Results]The endoscopic group proved significantly superior to the open group in terms of intraoperative blood loss[(115.8±13.1)ml vs(195.0±27.2)ml,P<0.05],postoperative ambulation time[(1.3±0.5)days vs(2.3±0.5)days,P<0.05]and hospi-tal stay[(10.1±1.2)days vs(14.1±1.8)days,P<0.05],but the former consumed significantly longer operation time than the latter[(115.1± 11.2)min vs(100.6±7.3)min,P<0.05].With time of the follow-up period lasted for(14.8±2.2)months on a mean,the VAS score and ODI sig-nificantly decreased in both groups(P<0.05),which was not statistically significant between the two groups before surgery(P>0.05),while those in the endoscopic group were significantly better than the open group 1 and 3 months after surgery(P<0.05),and then became not sta-tistically significant again between the two groups at the latest follow-up(P>0.05).Radiographically,the isthmic healing rate increased sig-nificantly over time in both groups(P<0.05),with no significant differences in isthmic healing quality and isthmic healing time between the two groups at any time points accordingly(P>0.05).By the time of last follow-up,all patients achieved isthmic bone healing.[Conclusion]The posterior endoscopic isthmic bone grafting and pedicle screw fixation is considerably better than the traditional open counterpart for lum-bar isthmic spondylolysis.