Admission to high-acuity intensive care units (ICUs) has been associated with improved outcomes compared to low-acuity ICUs, although the mechanism for these findings is unclear.Do high-acuity ICUs more effectively implement evidence-based processes of care that have been associated with improved clinical outcomes?We performed a retrospective cohort study of adult ICU patients admitted to 322 ICUs in 199 hospitals in the Philips eICU database between 2010-2015. The primary exposure was ICU acuity, defined as the mean APACHE IVa score of all admitted patients in a calendar year, stratified into quartiles. We used multivariable logistic regression to examine relationships of ICU acuity with adherence to evidence-based venous thromboembolism (VTE) and stress ulcer prophylaxis, and with the avoidance of potentially harmful events, including hypoglycemia, sustained hyperglycemia, and liberal transfusion practices (defined as red blood cell transfusions prescribed for non-bleeding patients with preceding hemoglobin ≥7g/dL).Among 1,058,510 ICU admissions, adherence to VTE and stress ulcer prophylaxis was high across acuity levels. In adjusted analyses, those admitted to low-acuity ICUs compared to the highest-acuity ICUs were more likely to experience hypoglycemic events (adjusted odds ratio [aOR] 1.12, 95% confidence interval [CI] 1.04-1.20), sustained hyperglycemia (aOR 1.07, 95% CI 1.04-1.10), and liberal transfusion practices (aOR 1.55, 95% CI 1.33-1.82).High ICU acuity is associated with better adherence to several evidence-based practices, which may be a marker of high-quality care. Future research should investigate how high-acuity ICUs approach ICU organization in order to identify targets to improve the quality of critical care across all ICU acuity levels.