The recognition that asthma is an inflammatory disease opens a new field to find effective models for the evaluation and development of new drugs. In this scenario, many novel candidate molecules have been shown to work perfectly in animal models, but not in clinical studies. Ancillary models are reviewed in association with the findings obtained in either transgenic or knockout mice. In parallel, genetic studies in animal models and human populations have identified several genes that are asthma-related. Knowledge of these recent findings, in parallel with pharmacogenomic studies will be necessary to direct new strategies for the development of novel drugs to treat subgroups of patients with asthma.