TY - JOUR AB - Purpose– Despite all the studies carried out in order to analyze the impact of quality management systems implementation and certification over companies' financial performance, conclusions reached so far have been of a contradictory nature. Some authors conclude that there is a positive relationship between ISO 9001 certification and companies' financial improvement, while others do not find evidence to support such a relationship. Overall, no consistent evidence could therefore be found in the literature concerning the ISO 9001 impact over companies' business financial performance. This work aims to provide a contribution in this area.Design/methodology/approach– Using a public database of Portuguese companies' financial information, this paper describes the results obtained from studying the economic impact of quality management systems, based on a statistical analysis.Findings– The results suggest that companies with higher financial performance do present a greater propensity to implement and certify their quality management systems. The ISO 9000 implementation motivation is a critical success factor in the impact of the quality management system over the company economic performance and, for some financial indicators, non‐certified companies do present, on average, higher performance than those that are certified.Originality/value– This paper aims to provide an important contribution to the worldwide research related to the quality management systems impact over companies' financial performance. VL - 28 IS - 9 SN - 0265-671X DO - 10.1108/02656711111172522 UR - https://doi.org/10.1108/02656711111172522 AU - Sampaio Paulo AU - Saraiva Pedro AU - Guimarães Rodrigues António PY - 2011 Y1 - 2011/01/01 TI - The economic impact of quality management systems in Portuguese certified companies: Empirical evidence T2 - International Journal of Quality & Reliability Management PB - Emerald Group Publishing Limited SP - 929 EP - 950 Y2 - 2024/05/09 ER -