Numerous pregnant women suffer from asthma and the use of asthma medications during pregnancy may be a necessity. Although some information is known about the effects of asthma medications during pregnancy, there is still a significant amount of information to learn and particular attention is required when prescribing drugs to these patients. In addition, physiological changes associated with pregnancy may affect airway responsiveness in some individuals. Guidelines on the management of asthma are published regularly, the most popular being the Global Initiative for Asthma (GINA), and medication can be prescribed during pregnancy when the apparent benefit of the drug is greater than the apparent risk. Usually, there is at least one 'safe' drug from each major class used to control symptoms. We will review the current literature on this subject.