This study aims to reveal the perspectives of enterprises that prepare sustainability reports among the top 100 companies in Turkey have on environmental sustainability. The extent to which businesses internalize environmental ethics can be analyzed by revealing their reporting styles. In this context, this study subjects 19 top- 100 enterprises’ sustainability or activity reports prepared following the Global Reporting Initiative (GRI) Standard criteria to content analyses regarding their environmental sustainability compliance activities and environmental sustainability awareness. As a result of the research, completely different approaches were encountered in how enterprises report their environmental attitudes of the enterprises based on their reported data. We consider the difference in the richness of the reported datasets to be directly related to the lack of sanctions ensuring standardization. When evaluating these companies approaches based on how they report on their environmental attitudes, enterprises have been revealed to vaguely explain or not mention at all the environmental themes about which they don’t want to be transparent. Although the GRI standard has no enforcement power, we believe it guides businesses toward socially responsible behaviors as it standardizes information sharing more transparently and increases accountability. In conclusion, the differences in criteria-based sustainability reports among enterprises is related to the voluntary basis of environmental reporting.