With expectations for resource efficiency and climate change adaptation in the construction industry, there is an increasing need for contractors to implement sustainable practices. Such action will burden contractors with additional costs that will lower their economic performance. There are few research studies on how sustainability relates to a firm's competitiveness. This paper represents an empirical study of the relationship between sustainability performance and business competitiveness of international construction contractors. An inverse U-shape relationship between contractors' sustainability performance and their international revenue, and a U-shape relationship between contractors' sustainability performance and their international revenue growth was discovered. The findings can help international contractors have a better understanding of the relationship between sustainability performance and business competitiveness, evaluate their current position in the relationship, optimize their resource allocation on sustainable development and integrate sustainability into their strategic planning. Therefore, contractors with high sustainability performance can expect higher international revenue growth, and sustainability performance is likely to become an opportunity for competitive advantage in the international construction market.