The high growth rate that the Vietnamese economy has been demonstrating in recent years largely depends on the use of the country’s fossil fuel reserves, which form the foundation of its fuel and energy sector. The country will have to rely on coal as one of the key energy sources for a long time in order to meet its energy needs. Since coal has been mined in Vietnam for a long time, the country is now facing such challenges as the depletion of readily available reserves and an increase in the share of coal mined underground in difficult geological conditions. These circumstances may affect the sustainability of the coal industry as a whole. The purpose of the study is to develop a method for analyzing the influence of geological conditions on production sustainability indicators at coal mines operated by Vinacomin, a state-owned corporation. Research methods include substantiating and choosing objects and indicators reflecting production sustainability at coal mines, formalizing the qualitative characteristics of geological conditions, and revealing the relationship between the complexity of geological conditions and production sustainability indicators. As a result of the analysis, the most problematic mines and their operations were identified. They should be given priority attention when developing measures and corporate programs aimed at fostering the sustainability of coal mines. The results of the study provide new knowledge on the coal industry in Vietnam and help to develop methods for assessing corporate sustainability.