There is great concern about waste and cooperation to move toward sustainable development. In response to this challenge, organizations are implementing practices to control consumption, reduce waste and reduce the negative impact on the environment through strategies that promote the Circular Economy (CE). However, the literature on the current understanding of circular strategies in nongovernmental organizations, such as charity shops, is limited. Therefore, this study aims to understand the social behavior of stakeholders (managers, sales assistants, buyers, and donors) who collaborate in a charity shop that uses CE strategies. To address this, the Theory of Planned Behavior (TPB) and stakeholder theory were used. Furthermore, the qualitative methodology of an exploratory case study was considered, which incorporated semi-structured interviews with 12 stakeholders who participated in the Chilean COANIQUEM charity shop. The results indicate that these organizations, through their different stakeholders with an environmental, social, and economic attitude, interact with one another and promote behaviors that favor circular strategies of reusing, recycling, and sharing in charity shops. These findings contribute to the CE literature in nongovernmental organizations and the TPB perspective by analyzing the attitude construct.