The membership of Slovakia in the EU affected extensively the field of environment protection regulations. An active approach of entrepreneurs to the environment protection regulation is conditioned by appropriate reliable information that should be a part of the company's Managerial Information System including information on environmental managerial accounting and calculations containing environmental costs of the actual output. The paper is focused on: — the need of environmental dimension of accounting and calculations; — the task of accounting and calculations providing environmental information important for environment protection management; — competitive advantage emerging from the active approach to the environment protection.