This article reviewed domestic and international studies on work engagement and considered the prospects for future studies from a viewpoint of effective utilization of the concept of “work engagement” in practice. Unlike other similar concepts (workaholism, job satisfaction, etc.), academic definitions of work engagement are characterized by high activity level and positive attitude/cognition regarding work. Using such a concept enhances interests and active involvements of both individuals and organizations as opposed to conventional mental health care in the workplace, which has focused mainly on prevention, and leads to a more effective practice. Previous studies have revealed antecedent and subsequent factors of work engagement, suggesting positive effects for both individuals and organizations. Meanwhile, although interventions to improve work engagement have shown some degree of effect through meta-analysis, contents and effect size are diverse among studies. In addition, the number of intervention effect studies is not large in Japan. From now on, process evaluation of introduction and implementation in real-life contexts is required. To promote evidence-based practice, it is necessary to not only develop more effective intervention programs but also study how to practice effective interventions.