Objective. To perform comparative analysis of the clinical efficacy and safety of indirect decompression of the spinal roots and interbody fusion through the lateral pre-psoas approach (OLIF) with anterolateral (OLIF-AF) and posterior percutaneous (OLIF-PF) screw fixations in the surgical treatment of single-segment lumbar stenosis.Material and Methods. A retrospective comparative analysis of treatment of 88 patients aged 29 to 72 years with single-level lumbar stenosis was carried out. Posterior instrumental fixation (OLIF-PF) was performed in 60 cases, and anterolateral (OLIF-AF) – in 28.Results. The compared groups did not statistically significantly differ from each other in terms of age, gender, body mass index, clinical picture and duration of symptoms before surgery, assessment of neurological status according to the Zurich Claudication Questionnaire (ZCQ), preoperative diagnosis, localization of stenosis, pain assessment in the back and leg before surgery according to a digital rating scale, physical status (ASA), health assessment (SF-12, ODI), follow-up period, as well as smoking and the presence of comorbidities (p > 0.05). In the OLIF-AF group, compared to the OLIF-PF group, a statistically significant advantage was found in terms of blood loss, duration of surgery and anesthesia, the level of radiological exposure, duration of patient’s hospitalization and hospital stay in the postoperative period, as well as the duration of antibiotic prophylaxis and intraoperative volume of infusions (p < 0.05). Despite earlier discharge and less use of local anesthesia (35.7 % vs 73.3 %; p = 0.001), patients in the OLIF-AF group had statistically significantly lower level of back pain on the day of discharge (3.0 vs 3.5; p = 0.034) and were less likely to need opioids (3.6 % vs 31.7 %; p = 0.003). With regard to complications and adverse events, there were no statistically significant differences during dynamic follow-up period from 3 to 50 months in both groups (17.9 % vs 28.3 %; p = 0.290), including depending on the timing of complications (early or late). In addition, no statistically significant differences were found for neurological, infectious, gastrointestinal, urological, or implant-related complications (p > 0.05).Conclusions. Indirect decompression of the spinal roots and interbody fusion through the lateral pre-psoas approach in combination with OLIF-AF is an effective and safe technique for the surgical treatment of single-segment lumbar stenosis. This method allows to reduce the invasiveness of surgery and severity of the pain syndrome and to create conditions for enhanced recovery after surgery. Further multicenter randomized trials are needed to comprehensively evaluate long-term outcomes.