There is increasing need to avoid excess opioid prescribing after surgery. We prospectively assessed overprescription in our hospital system and used these data to design a quality improvement intervention to reduce overprescription.Beginning in January 2017, an e-mail-based survey to assess the quantity of opioids used postoperatively as well as patient-reported pain control was sent to all surgical patients in a 23-hospital system. In January 2018, as a quality improvement initiative, guidelines were given to surgeons based on patient consumption data. Prescription and consumption were then tracked prospectively. Wilcoxon signed-rank, analysis of variance, and Cuzick trend tests were used to assess for overprescription and changes over time in opioid prescribing and consumption.We included 2239 patients in our cohort. The amount prescribed (median [IQR]: 30 [24-45] versus 18 [12-30], P 0.001) and consumed (median [IQR]: 12 [7-20] versus 8 [3-15], P 0.001) each decreased between the first and last quarter studied. Academic hospitals prescribed fewer opioids than nonacademic hospitals (median [IQR]: 24[15-40] versus median [IQR]: 30 [20-45], P 0.001). There was no difference in the quantity of opioids consumed between patients treated at academic and nonacademic facilities (median [IQR]: 10[3-19] versus 10.5 [4-20], P = 0.08). Patients consumed a median of 42% of the opioids prescribed, and there was no significant trend in the percent consumed over time (P = 0.8).Patients used far fewer opioids than prescribed after common adult general surgery procedures. When surgeons were provided with patient consumption data, the number of opioids prescribed decreased significantly.