Many developing countries, in particular Poland, are seeking avenues of compliance with ISO 14001 requirements. Polish enterprises should be concerned with its implementation in order to ensure competitiveness. The main objective of this study is to present an improvement procedure of the ISO 14001 environmental management system so that it could generate more benefits for enterprises. This procedure was developed on the basis of primary data collected in Podkarpackie Province enterprises with the use of a questionnaire. The main aim of the procedure was to identify desirable features of the system contributing to the enterprises’ better performance. The features of ISO 14001, essential for better performance, were attributed to the following stages of the environmental management system: commitment of all the workers, establishing procedures for achieving objectives and targets, establishing procedures for limiting impurities, conducting periodic internal audits, evaluating environmental performance, management reviews, and minimizing the negative influence on the environment. Positive correlations between the features development and the enterprise results allows for the treatment of the aforementioned determinants as the key features contributing to the economic results of the Podkarpackie Province enterprises. Opinions of the enterprises about ISO 14001 were not accidental, which was supported by Kendall’s coefficient of concordance.
Apart from financial result, net receipt and the enterprises’ efficiency, the increase in sales after ISO 14001 adoption was treated as a business performance indicator. With the use of chi2 test of independence it was shown that the period of using the ISO 14001 system influenced the increase in sales.