Abstract: Objective To investigate the effect of minimally invasive unilateral pedicle screw fixation and bilateral decompression in the treatment of single level lumbar spinal stenosis. Methods Total 91 cases of single level lumbar spinal stenosis in our hospital between April, 2014 and March, 2016 were divided into observation group (47 cases) and control group (44 cases). The patients in the observation group were treated with minimally invasive unilateral pedicle screw fixation and bilateral decompression, while control group with open bilateral fixation and bilateral decompression.All patients were followed up for more than one year. The operation duration, intraoperative blood loss, postoperative drainage flow volume, the time from the end of operation to post-operative ambulation, length of hospital stay, Oswestry disability index (ODI), visual analogue scale (VAS) and lumbar fusion situation were compared between the two groups. Results The operation duration, intraoperative blood loss, postoperative drainage flow volume, the time from the end of operation to post-operative ambulation and length of hospital stay in the observation group were significantly less than those in the control group (P<0.05); Compared with the data before operation, ODI decreased significantly in both groups at 1 year after the operation (P<0.05), and ODI had no significant difference between the two groups at 1 year after the operation (P>0.05); Compared with pre-operative data, VAS of leg and waist decreased significantly in both groups at 1 year after the operation (all P<0.05), and VAS of leg and waist had no significant difference between the two groups at 1 year after the operation (all P>0.05); Evaluation of Bridwell intervertebral fusion showed that, class Ⅰof the observation group was 31 cases, class Ⅱwas 16 cases, and class Ⅰ of the control group was 27 cases, class Ⅱwas17 cases, there was no significant difference between the two groups at 1 year after the operation (P>0.05). Conclusion Minimally invasive unilateral pedicle screw fixation and bilateral decompression has satisfactory efficacy, and mild trauma, rapid recovery in patients with single level lumbar spinal stenosis.