This study assesses the role of corporate social responsibility (CSR) in small and medium-size enterprises (SMEs) by reviewing 39 recent significant studies. The theoretical foundation of the reviewed studies serves as the basis for the research instrument designed to assess CSR practices and their impact on the competitive advantage of SMEs. A pilot study involving 102 Latvian SME respondents was conducted to validate the research instrument’s reliability across four scales: competitive advantage, reputation and financial performance, CSR domains and impact, and CSR challenges. The results indicate very good or excellent internal consistency, with Cronbach’s alpha values between 0.846 and 0.923. The findings demonstrate that SMEs continue to adopt CSR practices, recognising their strategic benefits which include innovation, operational efficiency and improved reputation. However, challenges such as resource limitations and stakeholder pressures remain important. This validated instrument establishes a foundation for further large-scale studies to explore CSR’s influence on the sustainability and competitiveness of SMEs, emphasising the need for tailored strategies, government support, and effective tools for evaluating CSR impact.