Recent studies investigating the developmental origins of lung diseases have started to delineate the effects of early life (pre-, peri- and postnatal) changes in lung development, environmental exposures and immune maturation on the development of childhood and adult lung diseases.  Taken together, external factors greatly affect pre- and postnatal lung development. Alterations in what is considered "healthy" lung development may prime the neonate for increased susceptibility to develop respiratory complications in later life. Although conceptually this viewpoint is widely accepted, the exact mechanisms underlying and time-frame in which these alterations take place remain to be unravelled. Investigations into the role of pre- and postnatal immune maturation and the influence of microbial composition on setting the immunological tone in early life will be discussed during the research seminar as research areas that need to be prioritized.