As asthma is the most common chronic disease in childhood, much attention is directed towards primary prevention. Here, the clinical effectiveness of a multifaceted educational prevention was studied.A total of 476 high-risk children were recruited during the prenatal period by general practitioners and randomised to either: 1) a control group, receiving usual care; or 2) an intervention group in which families received instruction from nurses on how to reduce exposure of newborns to mite, pet and food allergens, and passive smoking.A total of 443 infants were followed-up for 2 yrs. At 2 yrs of age, the intervention group (n5222) had less asthma-like symptoms, including wheezing, shortness of breath and night-time cough, than the control group (n5221). No significant differences in total and specific immunoglobulin E were found between the groups. During the first 2 yrs of life, the incidence of asthma-like symptoms was similar in both groups; however, subanalysis revealed a significant reduction in the female, but not in the male, intervention group.In conclusion, the intervention used in this study was not effective in reducing asthma-like symptoms in high-risk children during the first 2 yrs of life, although it was modestly effective at 2 yrs. Follow-up is necessary to confirm whether the intervention can actually prevent the development of asthma.