Developed countries report increasing trends in the prevalence of asthma and atopic diseases over the last 40 years. This change cannot be attributed to artefactual effects. Emerging from these information, new approaches have been generated to explore these novel findings. Among the most important new factors to be explored, scientific research is pointing out to variables related with physical environment, socio-economic and genetic background, anthrophometry at birth, nutritional status, diet, exercise and hormonal profile. Changes in the epidemiology of asthma and atopic conditions in developed countries were also preceded by increases in the prevalence of chronic diseases and their risk factors. Chile does not have information about time trends on these diseases, but several studies are reporting a high prevalence of asthma among adults. Conversely, results from the collaborative ISAAC study carried out in children, have shown a relative low prevalence of asthma in Chilean children. An increasing trend in chronic diseases and their risk factors has been reported in Chile, suggesting an epidemiological pattern similar to that experienced by industrialised countries, when the prevalence of asthma and atopic began to increase. This article review current information about etiological research emphasising the need to develop local research on asthma and atopic diseases taking into account our epidemiological situation