This book aims to analyze the seaport competiveness based on Resource-Based View (RBV) and Stakeholders approaches, in particular for the main seaport located in Portugal - Port of Sines. A case study methodology is used in order to collect all the information needed about its main resources and capabilities, and identifies the main stakeholders of seaport and to explain how those contribute to its competitiveness. Furthermore, we propose a conceptual research model in order to systematise the main resources and capabilities under which the competitiveness of the Port of Sines is built on and the influence of stakeholders.