As the world becomes increasingly aware of the negative impacts of human activity on the environment, there is an urgent need for sustainability. Small and medium-sized enterprises (SMEs) are essential contributors to the economy and their role in promoting sustainability cannot be overstated. This study examines the role of stakeholders in promoting the sustainable development of SMEs, with focusing on environmental sustainability and innovation. Specifically, it investigates the role of customers, local governments, competitors, and non-governmental organizations (NGOs). This study employs a qualitative approach using 10 semi-structured interviews to collect data from SMEs operating in Estonia. These findings suggest that stakeholder engagement is crucial for promoting the sustainable development of SMEs. While the government may not play an active role in promoting sustainability, NGOs, consumers, and competitors can all play an important role in supporting SMEs' sustainability efforts. These findings provide insights into the various stakeholders that SMEs should consider in their sustainability strategies and highlight the importance of collaboration and engagement with stakeholders to achieve sustainable development goals. The study contributes to the understanding of the role of stakeholders in promoting sustainable development in SMEs, specifically in the context of Estonia.