<h3>BACKGROUND CONTEXT</h3> Marijuana is an antinociceptive which has been evaluated as a possible adjunct or substitute for opioid use in the treatment of acute pain. The aim of this study was to evaluate the association between preoperative marijuana usage and consumption of opioids for postoperative analgesia. We hypothesized that marijuana usage may be associated with decreased usage of opioid analgesics in postoperative pain relief in patients undergoing spine surgery. <h3>PURPOSE</h3> To examine the association between marijuana use and opioid consumption in patients undergoing lumbar spine fusion surgery. <h3>STUDY DESIGN/SETTING</h3> Retrospective review. <h3>PATIENT SAMPLE</h3> Two hundred and twenty-one patients who underwent one- or two-level posterior lumbar interbody fusion surgery. <h3>OUTCOME MEASURES</h3> Primary outcome measures were opioid consumption in marijuana users and non- marijuana users both while in-patient and after discharge as determined by total morphine equivalent dose (MED). Secondary outcome measures included operative time, length of stay, discharge destination, and readmission rates. <h3>METHODS</h3> Retrospective review of 221 patients who underwent one- or two-level posterior lumbar fusion surgery between 2016 and 2020 at a single institution. Patients were categorized as marijuana users or non-marjiuana users based on preoperative diagnoses of marijuana use. Total morphine equivalent dose (MED) was calculated for both in-house opioid consumption and postoperative prescription opioid usage. Patients who were on opioids preoperatively were excluded. Patient demographics and preoperative characteristics were compared across the BMI cohorts using one-way ANOVA and chi-square analysis. <h3>RESULTS</h3> Of 221 total patients, 29 patients were identified as marijuana users while 192 were non- marijuana users. There were no significant associations between marijuana usage and age, ASA, BMI, tobacco use, EBL, OR time, LOS, or disposition to rehab. Marijuana users had greater association with depression (31% vs 12.5%, p=0.032) and 30-day readmission (17.2% vs 11.5% (p<0.001). Marijuana users were found to have increased opioid consumption in-house (MED 236.49 vs 166.68, p=0.005), as well as increased postoperative prescription opioid usage (2415.62 vs 1391.54, p=0.007). <h3>CONCLUSIONS</h3> Marijuana usage is associated with increased usage of opioids postoperatively, both while in patient and post-discharge, after posterior lumbar spine fusion surgery. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.