Objective: To examine the use of prescription opioids in patients undergoing major prostate and kidney operations. Methods: This is a prospective observational study that includes opioid naïve patients who underwent a major prostate or kidney operation from January 2017-May 2017. A telephone survey was conducted 3-4 weeks postoperatively. The survey assessed the number of 5 mg oxycodone-equivalents prescribed, opioid use, and disposal. Results: A total of 155 patients were included in our analysis. Most patients were male (86%), most were married (74%), the median was age 64 (interquartile range 59-70), and the majority were Caucasian (84%). Most patients reported social alcohol use (56%), but most denied current tobacco use (77%) or current and/or previous drug use (76%). Opioid prescribing exceeded use from 1.9- to 6.8-fold for all procedural categories. Overall, a total of 4065 oxycodone-equivalents were prescribed during this study and 60% of pills prescribed went unused. This resulted in 2622 excess pills in the community. Conclusion: Opioids are prescribed far in excess of need following major open and minimally invasive urologic procedures. Overall, 60% of prescribed opioids were unused. These data provide initial benchmarks for appropriate opioid prescribing after major prostate and kidney procedures. Future work to validate this initial guideline and improve patient counseling regarding appropriate perioperative opioid use and disposal is needed.