One in three patients with lumbar spinal stenosis (LSS) undergoing decompressive laminectomy (DL) to alleviate neurogenic claudication do not experience substantial improvement. This prospective cohort study conducted in 193 Veterans aimed to identify key spinal and extra-spinal factors that may contribute to a favorable DL outcome. Biopsychosocial factors evaluated pre-DL and one year post-DL were hip osteoarthritis, imaging-rated severity of spinal stenosis, scoliosis/kyphosis, leg length discrepancy, comorbidity, fibromyalgia, depression, anxiety, pain coping, social support, pain self-efficacy, sleep, opioid and non-opioid pain medications, smoking and other substance use. The Brigham Spinal Stenosis (BSS) questionnaire was the main outcome. BSS scales (Symptom Severity [SS], Physical Function [PF], Satisfaction [SAT]) were dichotomized as SAT<2.42, SS improvement≥0.46 and PF improvement≥0.42, and analyzed using logistic regression. Sixty-two percent improved in two of three BSS scales (i.e., success). Baseline characteristics associated with an increased odds of success were – worse BSS physical function (OR 1.24 [1.08-1.42]), greater self-efficacy for physical function (OR 1.30 [1.08-1.58]), lower self-efficacy for pain management (OR 0.80 [0.68-0.94]), less apparent leg length discrepancy (OR 0.71 [0.56-0.91]), greater self-reported alcohol problems (OR 1.53 [1.07-2.18]), greater treatment credibility (OR 1.31 [1.07-1.59]), and moderate or severe MRI-identified central canal stenosis (OR 3.52 [1.06-11.6]) moderate, OR 5.76 [1.83-18.1] severe). Using opioids was associated with lower odds of significant functional improvement (OR 0.46 [0.23-0.93]). All p<.05. Key modifiable factors associated with DL success – self-efficacy, apparent leg length inequality, and opioids, require further investigation and evaluation of the impact of their treatment on DL outcomes.