Throughout history the economies and industries have brought about a myriad of wealth and advantages to our modern world but these privileges and benefits have come at tremendous cost to our environment and nature. The third decade of the 21st century has already started; however, the most fundamental challenges and problems of the planet such as environmental pollution, global warming, climactic changes, extinction of spe- cies, deforestation, and reduction of natural resources, which affect both human and nonhuman beings, have still yet to be thoroughly addressed and resolved. Thus, this is a very critical point in history since the world as we know it may be on the brink of an irreversible disaster. This is an environmental crisis and requires urgent and effective solutions because it has both social and cultural consequences. Having a strong understanding of ethical responsibility to our fragile planet, environmental literature confronts these challenges and promises to raise a local and global awareness. Basically, it seems that establishing an awareness around processes that concern eco-systemic issues and relationships through writing or literature is one of the major characteristics of ecocriticism which has brought an influential dimension to literary and cultural studies. With its broad and flexible scope, environmental literature or ecocriticism does not only raise an awareness but also undertakes the ethical responsibility to reduce problems and subtly create a change in global mindsets in terms of highlighting the human-nature and human-nonhuman relationships in literature. Initiated in this crucial framework, this paper examines two medieval epic narratives, The Book of Dede Korkut and Beowulf, in Turkish and Anglo-Saxon cultures and discusses the comparative potentiality of these literary works through the theoretical lens of eco- criticism. In this study, new perspectives on old texts is opened up because they can provide a rich source of material for the ecocritical study of literature, which can ultimately bring forward a deeper and broader under- standing of both human and nonhuman. A comparative reading of The Book of Dede Korkut and Beowulf with a theoretical perspective of ecocriticism illuminates and confirms their immortality and relevance in our con- temporary world as both epics present a close and symmetrical interaction between human, animal and nonhu- man. Cognizant of the danger of imposing a universalist model that suppresses particular differences between two cultures, this study foregrounds that the literary worlds of Turkish and Anglo-Saxon cultures present a fundamental unity in terms of their approaches to environment. Highlighting the comparative relationships be- tween literature, culture and ecology as well as building an ecocritical bridge between the west and east, this study aims to foreground the significance of maintaining and safeguarding both a sustainable planet and intan- gible cultural heritages.