Background: Bronchiolitis is a viral lower respiratory tract infection in infants typically under a year of age clinically diagnosed with symptoms of upper respiratory tract infection progressing onto lower respiratory tract illness with respiratory distress and crackles, wheeze, and crepitation. The aim of this study was to estimate the incidence of pulmonary bacterial coinfection in children with acute bronchiolitis and assess the severity of bronchiolitis. Methods: This is a cross-sectional that included 100 children suffering from acute bronchiolitis to determine the incidence of bacterial coinfection in them that required admission to hospital for acute bronchiolitis. The cases were collected from pediatric department, Benha University Hospitals. Results: In our study, the incidence of hospital admission in the study participants was 82% of them, 46 (46%) patients were admitted to PICU, 36 (36%) patients were admitted to ward, and 18 (18%) patients were not admitted to hospital. We found that the isolated pathogenic bacterial coinfection in the study participants was 13%. The culture outcomes in the study participants showed that 6% patients were positive for Klebsiella, 5% patients were positive for Streptococcus, 2% patients were positive for both, and 87% patients were negative. Conclusion: Nearly 13% of the pediatric inpatients with RSV bronchopulmonary infection showed bacterial coinfection. The most common bacterial respiratory pathogens associated with RSV bronchopulmonary infection in children were 6% positive for Klebsiella, 5% positive for Streptococcus, 2% were positive for both, and 87% were negative.