This paper is based on detailed findings of a study of 40 Danish companies from a wide range of industries and with different levels of environmental performance. The study has two overall objectives. Firstly, to develop a simple tool for assessing the economic benefits/costs of environmental investments in the individual company. Secondly, based on the above, to calculate and assess some typical quantifiable savings, e.g. on energy and raw materials, over a period of four years (after the implementation of the integrated environmental management system). In line with other similar investigations, the study shows that the implementation of systematic and integrated environmental management systems results in significant savings. This supports the general, albeit rarely tested, hypothesis that it pays to be an environmentally responsible enterprise.