Asthma is one of the most important chronic diseases in childhood. For several decades, a steady increase in prevalence has been observed worldwide. In the structural collaboration between the Centre for Population Health Services in Edinburgh and the Research Institute CAPHRI of Maastricht we investigated the possibilities for primary prevention of asthma in childhood. We found that a multifaceted approach might be effective in delaying or preventing asthma, whereas a mono-intervention does not seem to have such a protective effect. The most likely explanation is that the development of a multifactorial disease, such as asthma, is extremely difficult, if not impossible, to prevent by eliminating only one risk factor. Underdiagnosis of asthma is still a big problem in primary care. Most patients do not present bronchial symptoms to the general practitioner, even though they have decreased lung function, so they remain unknown and undiagnosed. However, patients who do present with respiratory problems and who have reduced lung function are not always recognised as such. We found that the perception of dyspnoea seems to determine, at least in part, the presentation to the general practitioner with symptoms. These observations show that both the prevention of the development of asthma in early childhood, as well as case finding of asthma in adulthood, do not seem to be very effective in primary care. More research is needed to clarify what steps can be taken to reduce the global burden from asthma.