ISO14000 is an international environmental standard that acts as a guideline for companies to improve its performance in environmental aspects. Researches related to ISO14000 shows that the implementation has not only improved companies’ environmental performance, but this has also enhanced companies’ corporate performance. In this research, a project is carried out to determine the benefits and costs of ISO14000, which necessitates the inspections of companies’ performance in corporate and environmental aspects. A questionnaire survey was carried out to achieve this and s the results from the survey shows that ISO14000 had an excellent performance in environmental aspects such as reducing waste and usage of materials and energy. In the business aspects, however, the performances were average due to high time expense for this system maintenance and cost of certification and surveillance.