Arthroscopic rotator cuff repair (ARCR) is a common procedure that typically requires opioid prescription for postoperative pain management. To investigate the current prescription patterns and factors influencing 90-day postoperative opioid prescription trends for opioid-naïve patients who underwent ARCR. Case series; Level of evidence, 4. Opioid-naïve adult patients who underwent ARCR between January 2010 and September 2020 and had a record of opioid prescriptions during the 90-day postoperative period were identified in the PearlDiver Mariner91 national administrative database. Exclusions included patients with prior shoulder procedures, a history of chronic pain, and opioid prescription records dated earlier than 4 weeks before surgery. Covariates included age group, sex, Elixhauser Comorbidity Index, and prescriber specialty (orthopaedic or nonorthopaedic). The primary outcome-90-day postoperative morphine milligram equivalents (MMEs) prescribed per patient-was compared using univariate and multivariate regression analyses, and 90-day postoperative opioid prescription trends over the 10-year study period were analyzed with linear regression. In total, 55,345 ARCR cases were identified. The mean ± SD amount prescribed within the first 90 days was 742.4 ± 256.5 MMEs, and the median was 487.5 MMEs. Multivariate linear regression analysis predicted higher 90-day postoperative MMEs for female patients and younger patients (P < .01 for both). From 2010 to 2020, there was a 66% decrease in mean MME prescribed per patient (▵ = 660.4 MME; P < .01), with a mean reduction of 55.1 MME per patient per year. In 2020, the mean 90-day postoperative amount prescribed was 341.1 MME, which is equivalent to 51 tablets of 5-mg oxycodone (Percocet). Female sex and younger age were predictors of more MME being prescribed after ARCR. While opioid prescriptions following ARCR have substantially decreased over the past decade, the amount prescribed warrants further attention.