CONTEXT: Uncertainty exists as to which treatments are most effective for bronchiolitis, with considerable practice variation within and across health care sites. OBJECTIVE: A network meta-analysis to compare the effectiveness of common treatments for bronchiolitis in children aged ≤2 years. DATA SOURCES: Medline, Embase, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform were searched from inception to September 1, 2019. STUDY SELECTION: A total 150 randomized controlled trials comparing a placebo or active comparator with any bronchodilator, glucocorticoid steroid, hypertonic saline solution, antibiotic, helium-oxygen therapy, or high-flow oxygen therapy were included. DATA EXTRACTION: Data were extracted by 1 reviewer and independently verified. Primary outcomes were admission rate on day 1 and by day 7 and hospital length of stay. Strength of evidence was assessed by using Confidence in Network Meta-Analysis . RESULTS: Nebulized epinephrine (odds ratio: 0.64, 95% confidence interval [CI]: 0.44 to 0.93, low confidence) and nebulized hypertonic saline plus salbutamol (odds ratio: 0.44, 95% CI: 0.23 to 0.84, low confidence) reduced the admission rate on day 1. No treatment significantly reduced the admission rate on day 7. Nebulized hypertonic saline (mean difference: −0.64 days, 95% CI: −1.01 to −0.26, low confidence) and nebulized hypertonic saline plus epinephrine (mean difference: −0.91 days, 95% CI: −1.14 to −0.40, low confidence) reduced hospital length of stay. LIMITATIONS: Because we did not report adverse events in this analysis, we cannot make inferences about the safety of these treatments. CONCLUSIONS: Although hypertonic saline alone, or combined with epinephrine, may reduce an infant’s stay in the hospital, poor strength of evidence necessitates additional rigorous trials.