Objective To compare the efficiency and safety of transforaminal endoscopic spine system (TESSYS) with open operation in the treatment of lumbar spinal stenosis accompanied by osteoporosis. Methods Seventy-eight patients with lumbar spinal stenosis accompanied by osteoporosis undergoing surgical treatment in our department from March 2010 to September 2013 were recruited in this study. They were divided into 2 groups, TESSYS group (n=43) and open operation group (n=35). The degree of pain and lumbar function improvement were assessed using Visual Analogue Score (VAS) and Japanese Orthopaedics Association Lumbago Score (JOA) respectively, before and immediately after operation and at the end of follow-up. Operation time, bleeding volume and incidence of complications were compared between the 2 groups. Results There was no significant difference in VAS and JOA scores between 2 groups preoperatively (P＞0.05). After operation, the VAS scores were decreased (P＜0.05), and those of JOA were increased in both groups (P＜0.05), but there was no difference in the 2 scores between them (P＞0.05). While, the operation time, bleeding volume and incidence of complications were obviously less in the TESSYS group than in the open operation group (P＜0.05). Conclusion TESSYS has similar efficiency as open operation in the treatment of lumbar spinal stenosis accompanied by osteoporosis, but the former is superior in operation time, bleeding, and incidence of complications.