The need for recycling obsolete mobile phones has significantly increased with their rapidly growing worldwide production and distribution. Return and recycling rates are quite low; people tend to keep old, unused phones at home instead of returning them for recycling or further use because of a lack of knowledge and acceptance of return programmes. Thus far, individual use and recycling behavior has not shown any trend towards more sustainable patterns. Consequently, an increased awareness is needed for the high environmental and social impact throughout the whole value chain of a mobile phone—there is simply a lack of information and knowledge regarding sustainability issues around the mobile phone. A teaching material was therefore developed in a German research project, based on the concept of the ecological rucksack, presenting comprehensive information about the value chain of a mobile phone. Its application in different schools led to an increased awareness and interest among pupils for the connection between sustainability, resources and mobile phones. Based on these research results, this paper analyses young people’s knowledge of sustainability issues linked to their mobile phones and their acceptance of more sustainable behavioral patterns regarding their mobile, including return and recycling programmes.