Open AccessEnvironmental certification is considered as an advance to a company’s environmental management, in order to adapt its processes continuously, to reduce damage to the environment and avoiding compromising the quality of the community life. This study aims to find out what makes companies in the State of Rio Grande do Sul adhere to the ISO 14001 environmental certification, understanding their relationship with internal and external competitiveness, which is increasing worldwide due to globalization. The competitiveness of the market is so fierce, that to prevent the entrance of goods in certain countries, non-tariff barriers are created, such as the requirement of environmental certification standards. Even so, there is a low compliance rate to ISO 14001of companies in Rio Grande do Sul. Through researching, the reason has been found why that State has only six organisations certified: the high costs of implementation make it unfeasible for small and medium-sized companies which do not have sufficient funds for membership.