Dutch and Danish governments have applied a combination of voluntary and compulsory measures over the past decade in order to promote the development of more eco-friendly agriculture. This has brought the post-war intensification process in both countries to a halt, and to some extent even resulted in extensification. Voluntary environmental regulation aims at informing, educating and advising farmers or at influencing then values and attitudes. Such measures are often regarded as unimportant and inefficient, but recent surveys among farmers in Denmark and the Netherlands, and analysis of farmer study group schemes in both countries, question this assumption. A process of change in farmers' behaviour and attitudes can be observed, and voluntary measures seem to have played an important part. Farmers in close contact with extension, farmers participating in study groups, and 'green' farmers have shifted more quickly and decisively to eco-friendly methods than other farmers.