The vast majority of the world's plastic wastes are currently not (yet) recovered; they are either landfilled or released into the environment in an uncontrolled manner. This chapter focuses on the latter kind of plastic waste representing a global challenge for all actors in the plastics cycle and policymakers due to the huge volumes entering the environment and their negative environmental impact. Where unavoidable, these plastic wastes must first be collected and then gradually introduced as a resource into a circular plastics economy.pecial attention is given to the plastic pollution of the oceans—the marine litter problem. Based on the extensive literature on this topic, the causes and the ecological and further consequences of this global problem a summarized, together wit the current status of sources, input pathways and quantities, and existing and planned measures to combat the input of plastics into the environment. Finally, an attempt is made to give an overview of plastic pollution in Europe. Due to lacking data across Europe, available data for Germany are used exemplary.