The occurrence of abandoned, lost, and discarded fishing gear (ALDFG) in aquatic environments contributes both to environmental and socioeconomic impacts. In nature, discarded fishing gear contributes to pollution by macro- and microplastics and harmful chemicals as well as to the degradation of habitats. This study compiles information from the Nordic countries on the quantity and composition of lost fishing gear, originating mainly from sport- and recreational fishing activities. The study also considers the occurrence of harmful chemicals associated with the lost fishing gear and the potential impact of these chemicals on the aquatic environment. Suggestions on how to prevent further losses and mitigate negative impact of lost fishing gear are also provided.