Some studies indicate that children born to younger mothers are at a higher risk of wheezing and asthma. To investigate the maternal age associated with asthma in children, a case-control study on 310 asthmatic and 310 non-asthmatic children aged 3 to 4 years was organized during a one-year period. A questionnaire was used to obtain information about the child’s personal susceptibility factors, family history of asthma and past infectious diseases, environmental exposure, and sociodemographic characteristics. In comparison with children of mothers who were 30 years of age or older, children of mothers aged 26-30 years had an adjusted odds ratio of 0.99 (95% CI= 0.37-2.64) of developing asthma; children of mothers between 21 and 25 years had an odds ratio of 1.60 (95% CI = 0.47-5.40), and those whose mothers were 20 years old or younger had an odds ratio of 6.74 (95% CI = 1.23-36.72). Younger mothers have children with a greater risk factor of childhood asthma.