Bronchiolitis is probably the most familiar, most “bread-and-butter” entity in pediatrics. Yet, after decades of clinical and basic investigation, clinicians have no specific therapies at hand and we are far from a complete understanding of the pathogenesis or sequelae of this illness. The article by Mansbach et al1 in this issue of the Archives highlights the extent to which we are still in the dark about bronchiolitis and how to manage it and makes 2 important contributions to this field: it demonstrates that coinfection with multiple respiratory viruses is more common in bronchiolitis than anticipated, and it establishes that the presence of human rhinovirus (HRV), either alone or as a partner in coinfection, affects the length of hospital stay for children with bronchiolitis.