INTRODUCTION: The aim of our study was to determine if human metapneumovirus (hMPV) and Chlamydophila pneumoniae (CP) could be detected in Singaporean asthmatic children and wheezing infants during an acute asthma attack. METHODS: The study was performed on 30 older children (mean age 9.8 years) and 30 young children (mean age 1.3 years), who were admitted with an acute exacerbation of wheezing. Nasopharyngeal aspirates were collected and tested by polymerase chain reaction for CP, and for a panel of viruses (hMPV, respiratory syncytial virus, adenovirus, influenza virus types A and B, parainfluenza virus types 1 and 3, and rhinovirus). RESULTS: hMPV was isolated in eight out of 60 children (13.3 percent), while CP was isolated in two cases. Overall, 48/60 (80 percent) samples were positive for the presence of viruses. CONCLUSION: In most of the children admitted because of acute wheezing, a virus could be detected. hMPV was isolated for the first time in Singapore in children who were admitted with an acute asthma attack.