In the first decade of the twenty-first century Non-Traditional Security (NTS) challenges are of rising importance due to their increasing impact on daily life and broader national interests. This paper focuses on the Mekong Region as an important subregion due to its significance for more than 70 million people living directly on the river banks and its importance for the economic development of the six riparian countries. This paper investigates NTS challenges in the Mekong Subregion with a focus on environmental challenges and argues that NTS are of increasing importance in the region and will increase in the future. Whereas economic growth is crucial for the improvements of the livelihoods on the Mekong River and the overall economic performance of the riparian states, environmental protection cannot be disregarded as doing so would have devastating impact on the subregion and the wider region in the future.