This study surveys a sample of 162 public listed companies on the Kuala Lumpur Stock Exchange. The study utilises eight different measures of company performance, ROA, ROE, WC, ROS, CF, TQ and EVA, and five company's attributes, namely size, growth. capital structure, age and industrial category. The analyses revealed that ISO registered Malaysian companies outperformed their non-ISO registered counterparts during the period of this study. This study finds that ISO 9000 registered companies in Malaysia are better off than non-ISO 9000 registered companies in terms of performance measures ROA, ROS and WC, except for EVA. ISO 9000 registered companies are younger, larger, and have a higher growth and a lower capital structure than non-ISO 9000 registered companies.