Importance: Hospitalizations of infants for bronchiolitis are common and costly. Despite the high incidence and resource burden of bronchiolitis, themainstay of treatment remains supportive care, which frequently includes nasal suctioning. Objective: To examine the association between suctioning device type and suctioning lapses greater than 4 hours within the first 24 hours after hospital admission on length of stay (LOS) in infants with bronchiolitis. Design: Retrospective cohort study. Data were extracted from the electronic health record. Setting: Main hospital and satellite facility of a large quaternary care children's hospital from January 10, 2010, through April 30, 2011. Participants: A total of 740 infants aged 2 to 12months and hospitalized with bronchiolitis. Main Outcome Measure: Hospital LOS. Results: In the multivariable model adjusted for inverse weighting for propensity to receive deep suctioning, increased deep suction as a percentage of suction events was associated with increased LOS with a geometric mean of 1.75 days (95% CI, 1.56-1.95 days) in patients with no deep suction and 2.35 days (2.10-2.62 days) in patients with more than 60% deep suction. An increased number of suctioning lapses was also associated with increased LOS in a dose-dependent manner with a geometric mean of 1.62 days (95% CI, 1.43-1.83 days) in patients with no lapses and 2.64 days (2.30-3.04 days) in patients with 3 or 4 lapses. Conclusions and Relevance: For patients admittedwith bronchiolitis, the use of deep suctioning in the first 24 hours after admission and lapses greater than 4 hours between suctioning events were associated with longer LOS