||The implementation of environmental accounting in Natural Reserves produced some significant results in terms of restrictions. First of all, environmental accounting introduced a limitation in scale, which was inapplicable on a micro scale. A second restriction concerned the physical unit measure that was used instead of a monetary unit measure. Finally, a third limitation was due to the fact that environmental accounting takes into account only costs, not environmental benefits. These three limitations led us to develop an environmental accounting model that considered resources in the Natural Reserve, both consumed and produced. The model applied to Miramare Natural Marine Reserve (Italy) aimed to supplement monetary accounting based on cost and revenue with environmental accounting which reflects not only environmental cost but also environmental revenues, i.e. environmental benefits. Environmental cost took into account anthropic presence, raw materials use, consumption of fuel for motor vehicles and heating fuel, consumption of electricity, water consumption, and administration expenses. Environmental benefits assessed ecosystem functions: gas regulation, nutrient cycling, biological control, food production, recreation, and culture. The difference between costs and benefits, both economic and environmental, represented the value produced or consumed by the Natural Reserve. The model demonstrated that the net benefit for the Reserve was approximately €654,000 covering the amount of public transfer (about €610,000) completely.