Organizations in the Third sector operating in non-Western contexts need to have enhanced governance models that match the need to ensure ethical and efficient commercial operations within their mission. The key research question of present article is how the implementation of GCG in Slovenian NGOs will contribute to strengthening their legitimacy, stakeholder trust, and effectiveness in achieving social goals. The article develops a conceptual model which should include all key variables, mediators, moderators and latent constructs in itself, serving as a theoretical basis for future empirical studies and best practices. The main finding is that the GCG should be organized as a single-track administrative body of public institutes in the future. Better single-truck GCG regulations, which would presuppose amendment of legislation, can be created and executed in practice only by working together, with the public, regulatory agencies, academic community, NGOs, and prominent intellectuals.