Most information on invasive alien pests is available for the leeward Dutch islands while the least is known for the windward Dutch islands. The principal means of entry is the importation of unsterilized soil and plant material through container shipment, import of ornamental plants and air traffic. The economic costs, both in terms of damages and control measures, as well as missed opportunities that these species cause, has not been estimated but certainly runs in the millions of dollars annually. By far the most economically costly invasive species is the yellow fever mosquito Aedes aegypti, a pest and disease vector closely associated with man. In a few cases, biological control and eradication has been successful. Introduction of invasive pest species continues at a high rate in the Dutch Caribbean and preventive measures are urgently needed to limit future costs and risks in terms of economy and health.