The European Commission launched a renewed agenda for adult learning with the objective of ensuring access to high-quality educational opportunities to adult learners for the promotion of their personal and professional development. Thus, European researchers in this field are paying attention to lifelong learning actions in order to address this challenge. Studies in this area are exploring how adult education can strengthen adults’ skills, in particular those required in the current knowledge society (information and communication technologies, problem solving, foreign languages, etc.). Simultaneously, some investigations focus in depth on the role that adult education can play in overcoming social exclusion for the most underserved groups. This paper describes the contributions of these investigations as well as the steps carried out by programs and theories that have contributed the most to adult learning. Lastly, future developments and challenges on this field are explained.