Policy-makers, professionals of all kinds and the general public increasingly recognize social and economic factors as important determinants of health. Because health promotion approaches address these factors, they can play a valuable role in protecting and improving health. At the same time, funding sources demand evidence that initiatives give value for money. Health promotion initiatives need effective evaluation to realize their potential: both to prove their value as investments and to increase their effectiveness in achieving their aims. To help meet this need, the WHO European Working Group on Health Promotion Evaluation examined the current range of qualitative and quantitative evaluation methods to provide guidance to policy-makers and practitioners.