This chapter explains eye movements during collaborative problem-solving. Collaborative problem-solving means resolving difficulties and working toward a goal during social collaboration with others. Social life is filled with collaborative problem-solving tasks, such as group work in schools or workplaces. Understanding behavioral signals is one important step in improving performance in collaborative problem-solving. We focus on eye movements as an example in this section. We show the analyses of eye movements related to social performance and discuss future directions for investigating eye movements to improve collaborative problem-solving.