Security and safety share fundamentally important features as operational activities with the goal to protect people, property, and the smooth economical functioning of organizations and society. In safety-critical industries, safety is seen as the positive outcome of management of problems and trade-offs that are rooted in systems' complexity, goal interaction, and resource limitations. This perspective has led safety research to shift focus and go beyond individual acts and move to systematic aspects of human, technological, and organizational performance. It involves dealing with problems connected to regulations and standardized procedures, technology and automation, and efforts to understand the impact of communication, group dynamics, leadership, and culture on safety. In spite of distinct differences in the nature of threats (intentional/unintentional), there are many areas (use of standardized procedures, human factors training, and modeling for increased understanding of adverse events) where knowledge and experiences from safety operations can fruitfully spill over to security. To establish cooperation between these two fields, for example on regulatory and procedural development, training and simulation, as well as operational evaluation, would be to produce synergies not yet known today.