Purpose: We document the postoperative opioid use in 749 consecutive patients after Anterior Cruciate Ligament Reconstruction (ACLR). We define three groups of total postoperative opioid usage: 0-1 week, 1-2 weeks and greater than 3 weeks; and define characteristics correlated to each group. Postoperative opioid used was measured by the number of prescriptions given. Methods: Opioid was prescribed in quantities not to exceed a one-week supply. In Group 1, a single prescription of opioid converted to a maximum of 300-375 Morphine Milligram Equivalent (MME) or less(which is equivalent to hydrocodone 7.5 mg per tablet with a total number of 40-50 tablets or less). In Group 2, two prescriptions of opioid, converted to 376-750 MME. In Group 3, three prescriptions or more converted to 751 or greater MME. The following demographics and characteristics were identified for each group: age, gender, tobacco smoke, regular alcohol use, diabetes, anxiety or depression, worker's compensation, history of chemical dependence, and history of intravenous drug use. The following concomitant surgical procedures were identified for each group: menisectomy, chondroplasty, meniscal repair, and microfracture. Results: The great majority of patients, 634 (85%), were in Group 1 requiring no more than a single prescription, one week or less, of opioid. The 115 patients (15%) that exceeded the typical range of the Group 1 opioid requirement (Group 2 & 3) had a statistically significant (p<0.05) association with increased age, alcohol usage, tobacco smoking; anxiety or depression (Group 2 only); and concomitant microfracture. Conclusion: We recommend limiting the initial opioid prescription not to exceed a one-week supply or less (300-375 MME or less) after ACLR. This amount satisfied the opioid requirement for 85% of our patients undergoing primary allograft ACLR. In the last year of this study, opioid prescription did not exceed 300 MME and no opioid prescription exceeded forty tablets. Increased age, alcohol use, tobacco smoking, anxiety or depression and microfracture were significantly associated with increased opioid usage. Clinical Significance: This information should help leave fewer unused opioid in the possession of patients, leaving fewer pills vulnerable to misuse, abuse, and diversion. Another goal would be to use this information to help develop a postoperative pain management protocol or guidelines after ACLR.