Recently published intervention studies and their implications for Switzerland. Recently published results of large scale intervention studies (Multiple Risk Factor Intervention Trial, MRFIT, and European Intervention Study, World Health Organization European Collaborative Group) seem to question, according to some observers, the basis of population oriented cardiovascular prevention. As the National Research Program 1A "Prevention of Cardiovascular Disease in Switzerland" was based on the same assumptions regarding the relationship of risk factors and cardiovascular disease, the authors discussed the implication of the two studies for Switzerland. A detailed analysis of the European Intervention Study shows, that in spite of the overall non-significant mortality reduction of 8% there were important differences between participating countries, With significant differences in Belgium and Italy, both with innovative health education programs. MRFIT shows an important reduction of risk factors also in the control group, indicating a beneficial effect of "usual care" by practising physicians. Together with the recent recommendations of a WHO expert committee the authors conclude, that the two studies do not invalidate the principles of cardiovascular prevention.