In the last decade, business process management (BPM) has become essential for corporations to maintain their control over business processes. Therefore it is highly important for companies to know which factors influence business process performance. Consequently, this study focuses on the relationship between BPM maturity and BPM performance. The paper aims to determine (1) whether BPM maturity has a significant effect on BPM performance and (2) whether there is a significant difference between a country that is in a relatively more mature stadium with regard to BPM practices and one that is still going through an adapting phase. In this case we compared the Netherlands and Portugal, in which Portugal reflects the country that is going through an adoption phase. A total of 138 Dutch and 58 Portuguese companies responded to an online survey about BPM practices. For this research, 29 Dutch and 12 Portuguese commercial companies with at least 1,000 employees were taken into account. Statistical empirical research shows that BPM maturity has a significant positive effect on BPM performance. It also shows that although the effect is positive in both countries there is a significant difference between the Netherlands and Portugal. The effect of BPM maturity on BPM performance is higher in Portugal than in the Netherlands. The research concludes that large commercial companies in both countries can attain a better BPM performance by raising their BPM maturity.