Aims : To describe and highlight the use of animal-free methods in respiratory research. Animal experiments have been widely used in respiratory research, and have provided important information. In the last decade, numerous in vitro, ex-vivo and in-silico methods and models have been developed that are useful in respiratory research and that can at least in part replace animal models. This is important not only in view of the ethical issues concerning the use of animal models, but also because of the difficulty in translating observations made in animals to the human situation.