Continuous pulse oximetry monitoring in stable patients with bronchiolitis is discouraged by national guidelines in order to reduce overuse, yet wide practice variation exists among hospitals. Understanding the association between monitoring overuse and hospital unit-level factors may identify areas for improvement. Conducted at 25 sites from the Pediatric Research in Inpatient Settings (PRIS) Network's Eliminating Monitoring Overuse (EMO) study, this substudy used data from 2,366 in-person observations of pulse oximetry use in patients with bronchiolitis to determine whether hospital unit-level factors were associated with variation in pulse oximetry use for patients in whom continuous monitoring is not indicated. Hospital units were classified by bronchiolitis admission burden. Monitoring rates were analyzed in a mixed-effects model that accounted for variation in baseline monitoring rates among hospitals and adjusted for covariates significantly associated with continuous pulse oximetry monitoring use in the primary study's analysis. Low burden units (<10% of total admissions) had a 2.16-fold increased odds of pulse oximetry overuse compared to high burden units (≥40% of total admissions) (95% CI, 1.27-3.69; P = .01). These results suggest that units caring for a lower percentage of patients with bronchiolitis are more likely to overuse pulse oximetry despite national guidelines.