Matrix metalloproteinase 9 plays an important role in the development of bronchial asthma. We were interested in whether the polymorphisms -T1702A, -C1562T, R279Q and +C6T within the matrix metalloproteinase 9 (MMP-9) gene were associated with asthma in a population of 231 asthmatic children. However, we found no association. Thus MMP-9 might not be a major gene for asthma.