Nature-based solutions attract more and more interest due to increasing maintenance costs of grey infrastructure, increasing design conditions and growing environmental awareness. Integrating ecosystems in coastal engineering practice not only scores with societal and ecological benefits, such as biodiversity and cultural services, but also provides coastal protection services by attenuating waves and stabilizing sediments. Although nature-based solutions can already be found along many coasts around the globe, coastal engineers are still posed to challenges when evaluating, designing, implementing or maintaining nature-based solutions as guidance and in-depth investigations on efficiency, vulnerabilities and natural dynamics are often lacking. Current challenges for science and practice relate to the general requirements of nature-based solutions, the determination of fundamental data and insecurities and knowledge gaps. To overcome these challenges, close collaboration of engineers and ecologists is necessary.