In the past few years, an increasing number of Private Security Companies (PSCs-sometimes also referred to as Private Military Companies, PMCs [1]) have emerged and are offering and conducting maritime security services in Southeast Asia. These companies offer services in addition to security provided by Southeast Asian states and their government agencies. This paper explores the role of private companies in securing vessels, ports, offshore energy installations and fishing grounds across Southeast Asia, and discusses whether PSCs are an alternative or viable supplement to government efforts to protect national waters, shipping lanes and other maritime assets.