Abstracts: Asthma is a chronic airway inflammation in which the acute periods in combination with the remission periods. Viral respiratory infection, especially Rhinovirus (RV) has been seen as the main trigger induced asthma exacerbation in both adults and children. This study was conducted to indentify the prevelance of Rhinovirus infection in children with acute asthma and evaluate some features of acute asthma induced by RV. This was a discriptive and prospective study in children with acute asthma under 15 year of age. The results showed that there were 146 childhood asthma in acute periods, and 72.6 percent of them were infected RV. Children with RV infection had higher risk of seveve asthma exacerbation compared with children without RV infection (OR=5.1
95 percent CI: 1.69-15.44), wheezing was often seen in RV infected children. The pecentage of white blood cell in RV infected group were 68.5 percent compared to 45 percent in .non RV infected group, it was statistically sinificant difference (p0.05). The pecentage of blood eosinophils were 34.9 percent in RV infected children in comparison to 15 percent in non RV infected children. Conclusion: Rhinovirus infection was the main trigger induced asthma exacerbation in children and increased risk of seveve acute asthma.