Temperate anguillid eels are enigmatic species that have captured the curiosity of scientists for hundreds of years, and have also historically been exploited as a fisheries resource. In particular, fishing of American, European, and Japanese eels has been consistent, and severe declines in population size have been observed since the 1970s. Scientists and resource managers have been studying eel biology and fisheries to understand the status of eel resources and the causes of eel population decline. However, many knowledge gaps remain owing to the limited scientific data and knowledge on specific aspects of eel biology, ecology, and the interacting effects of changes in marine and freshwater environments and human activities. In this chapter, we provide an overview of the current state of Japanese eel resources and their management through the regulation of fishing, aquaculture, and trade. The first half summarizes the latest assessment of eel resources and describes the challenges for data collection and knowledge generation owing to the complex life cycle of the Japanese eel and numerous uncertainties related to its ecology. The key challenge is to improve the accuracy and timeliness of the temporal and spatial data obtained from catch statistics and field research. The second half outlines the updated domestic regulations for Japanese eel catch/fishery and aquaculture and the ongoing international efforts to conserve Japanese eel resources. Resource managers have implemented a variety of policies and tools based on the best scientific knowledge available while generating a collective will among countries/regions to adopt a coordinated approach to conserving Japanese eel resources.