To examine the impact of Patient-Reported Outcomes Measurement Information System (PROMIS) Sleep Disturbance (PROMIS-SD) on clinical outcomes in patients undergoing lumbar decompression. Patients undergoing lumbar decompression with preoperative PROMIS-SD scores were retrospectively included. Patients were separated into 2 cohorts: none to slight sleep disturbance (PROMIS-SD <55) and mild to severe sleep disturbance (PROMIS-SD ≥55). Patient-reported outcome measures including PROMIS Physical Function, PROMIS Anxiety, PROMIS Pain Interference, PROMIS SD, 9-item Patient Health Questionnaire, visual analog scale back/leg, and Oswestry Disability Index were collected preoperatively and up to 1 year postoperatively. Of 87 patients identified, 48 patients had PROMIS-SD scores ≥55. Regardless of preoperative PROMIS-SD score, patients reported significant improvement in physical function, anxiety, pain interference, depression, pain, and disability outcomes in at least 1 time point. Patients in the PROMIS-SD ≥55 cohort reported postoperative improvement in sleep disturbance. Patients in the PROMIS-SD <55 cohort reported superior preoperative patient-reported outcome measures in all domains and superior postoperative improvement in pain interference and sleep disturbance. Minimum clinically important difference attainment rates were higher in the PROMIS-SD ≥55 cohort in physical function, anxiety, pain interference, sleep disturbance, and pain. Patients undergoing lumbar decompression demonstrated significant postoperative improvement in most clinical outcomes regardless of preoperative sleep disturbance. Patients with mild to severe sleep disturbance had higher minimum clinically important difference attainment rates for physical function, mental function, and pain. Patients undergoing lumbar decompression with greater preoperative sleep disturbance may experience more clinically noticeable improvement.