This article examines COSCO’s investment in the Port of Piraeus in Greece, which provides a good example of economic cooperation between China and Greece against the backdrop of the Belt and Road Initiative. It argues that investment in the Port of Piraeus has had a positive impact on the development of Greece by stimulating infrastructure investment, enhancing the competitiveness of the port, boosting the local economy, and helping to attract more foreign investment. However, the article also identifies potential challenges for Sino-Greek economic cooperation in the long run. Structural obstacles and concerns from European countries could affect China’s investment in Greece as well as Sino-Greek economic cooperation in the future.