A study of the European biological control literature leads to the conclusion that importation of arthropods for biological control of pest arthropods has not led to unwanted side effects. Current pest control policies in many European countries support or stimulate biological control, and the number of natural enemy imports has increased during the past three decades. At the same time, development of rules is making import and release of non-indigenous beneficial organisms very difficult. It is of great importance to find a balance between reasonable regulation of importation and release of new candidates for biological control and the possibility to develop sustainable, environmentally safe pest control. Use of non-indigenous microorganisms for biological control is covered by the national registration procedure of each European country. For macro-organisms, European countries have very different criteria for importation and release. Standardization of rules for importation of non-indigenous organisms is under discussion within the European Union (EU) and European and Mediterranean Plant Protection Organization, and there are efforts to include elements of the Food and Agriculture Code of Conduct for the Importation and Release of Biological Control Agents into the EU regulations. Regulation of importation of natural enemies may be needed, but such ruling should preferably be developed by both scientists and biological control practitioners. Very strict regulation procedures for biological control agents will result in more damage to the environment because of the continued use of chemical pest control and will erode the motivation of those with an honest approach to developing environmentally friendlier alternatives.