This study evaluates the economic and environmental sustainability of protein-rich crops (quinoa, faba beans, chickpeas, and lentils) cultivated in Europe. Using life cycle assessment (LCA) and life cycle cost (LCC) analyses, it examines the impacts of these crops grown in the Netherlands, Spain, and Italy under both organic and conventional farming methods. Unlike previous agri-food studies that mostly assess sustainability dimensions in isolation, this research integrates LCA and LCC to provide a comprehensive eco-efficiency evaluation, offering novel insights into the trade-offs between environmental impact and economic viability. In addition, this study focuses on the cultivation of four protein-rich crops that are novel to Europe. The results reveal significant variability in environmental impacts, including climate change impact and land use, as well as profitability, across different crops, countries, and farming practices. Dutch conventionally grown faba beans demonstrate the highest eco-efficiency, while organic lentils in Italy and organic quinoa in the Netherlands also perform well. The study highlights the instability of crop yields and suggests that local production of these protein-rich crops could reduce Europe's dependency on imported soy, although careful consideration of regional suitability and farming methods is necessary. The findings aim to guide farmers and policymakers in promoting sustainable protein-rich crop production in Europe.