The purpose of this study is to examine the relationship between staff members’ daily chats in a refresh room during break times and their knowledge sharing in the workplace, using a subjective questionnaire survey and statistical analysis relying on a social psychological methodology. The data was gathered from staff in a Japanese hospital and a hierarchical regression analysis and a simple slope analysis were conducted. As a result, it was found that among those who seldom participate in refresh room chats, staff members who frequently talk about positive job experiences when they do occasionally participate are likely to evaluate their knowledge sharing better than others who do not often talk so. In addition, among those who do not discuss positive job experiences, staff members who often participate in chats are likely to evaluate their knowledge sharing better than those who participate less often. Therefore, the development of measures both to promote participation in chats and to enable and encourage staff to talk about positive job experiences will be recommended in order to foster effective knowledge sharing.