Due to the importance of the identification and classification of stakeholders in the elaboration process of the sustainability reports and, facing the risk of considering arbitrarily to louder individuals or groups or those related or closer to owners or managers, we aim to analyze the application of criteria and procedures leading to an adequate determination of stakeholders. With the purpose of illustrating in a practical way the criteria and procedures used, we describe the profile of a PyME in the process of making its first sustainability report. We applied the criteria established in the AA1000SES Standard of AccountAbility (2011) to the proposal published in a learning journal of the Global Reporting Initiative (GRI). The methodological application performed allowed us to identify in a truly representative way, for this company, its interest groups and to establish priorities to contact them. The stakeholder mapping performed is consistent with the sustainability concept: it considers the economic, social, and environmental aspects; covers present and future seasonality; and also the consequences of the reciprocal actions between the stakeholders and the company.