<h3>BACKGROUND CONTEXT</h3> Cigarette smoking has been shown to have detrimental effects on patient reported outcomes (PROs) and fusion with lumbar arthrodesis. However, the evidence is not clear as to whether smoking affects PROs in patients undergoing decompression only. <h3>PURPOSE</h3> The purpose of this study was to determine if smoking status affects PROs following decompression for lumbar disc herniation (LDH) or lumbar spinal stenosis (LSS). <h3>STUDY DESIGN/SETTING</h3> Retrospective review of prospectively collected data from Quality Outcomes Database (QOD). <h3>PATIENT SAMPLE</h3> Patients enrolled in QOD at multiple sites who underwent 1 or 2-level decompression only for LDH or LSS. <h3>OUTCOME MEASURES</h3> Back and leg pain scores (0-10), Oswestry Disability Index (ODI) and EuroQoL 5D-3L (EQ-5D) at baseline and 12 months postoperatively. <h3>METHODS</h3> Patients who underwent 1 or 2-level decompression only for LDH or LSS were identified. Standard demographics, surgical variables, smoking status and PROs at baseline and 12 months postoperatively were collected. Outcomes were compared between smokers and nonsmokers. A sub-analysis of propensity-matched cases was also performed. <h3>RESULTS</h3> Of 17,271 patients identified, 3,038 were smokers and 14,233 were nonsmokers. Smokers were younger (50.3 vs 56.7, p < 0.000), had worse ASA grades (2.3 vs 2.2, p < 0.000) and had a greater proportion of males (1663, 55% vs 7130, 50%, p < 0.000) compared to the nonsmokers. The mean number of levels decompressed was similar between the two groups (1.7, p=0.169). For all PROs, both smokers and nonsmokers improved following surgery. Preoperative PROs in smokers were significantly worse (p < 0.000) for back pain (7.0 vs 6.1), leg pain (7.4 vs 6.9), ODI (52.2 vs 45.9) and EQ-5D (0.5 vs 0.6). PRO improvement in smokers was statistically less than in nonsmokers at 12-month follow-up (p < 0.001), but the differences may not be clinically relevant: back pain (3.2 vs 3.3), leg pain (4.3 vs 4.6), ODI (25.0 vs 26.8) and EQ-5D (0.24 vs 0.26). The percentage of patients reaching minimally clinically important difference (MCID) were significantly less in smokers for ODI (68% vs 74%, p < 0.001), leg pain (73% vs 79% p < 0.001) and back pain (75% vs 78%, p=0.005). Consistent with the differences at baseline, only 60 LSS cases and 38 LDH cases could be propensity matched. In this sub-analysis, there were no statistically significant differences in the improvements in PROs in the LSS group between smokers and nonsmokers (δBP:3.2 vs 3.5, p=0.577; δLP:3.3 vs 4.5, p=0.097; δODI:18.1 vs 23.5, p=0.155; δEQ5D: 0.2 vs 0.2, p=0.948). There were no statistically significant differences in the improvements in PROs in the LDH group between smokers and nonsmokers (δBP:3.1 vs 3.7, p=0.530; δLP:3.7 vs 5.3, p=0.050; δODI:24.6 vs 28.6, p=0.463; δEQ5D: 0.2 vs 0.3, p=0.301). There were no statistically significant differences in the proportion of smokers vs nonsmokers reaching MCID, except for leg pain in the LSS cohort (53% vs 75%p=0.022). <h3>CONCLUSIONS</h3> Although nonsmokers demonstrated statistically greater improvement in all PROs and were more likely to reach MCID, these differences are relatively small. These differences became even less evident in a small propensity-matched sub-analysis. As compared to fusion surgery, both smokers and nonsmokers treated with decompression only for LDH or LSS exhibit significant clinical improvement in PROs. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.