The purpose of this study is to comprehensively analyze and evaluate the ecological, partly geographical and hydrological, characteristics of the Araz River. The study was conducted in several locations of the Nakhchivan Autonomous Republic. Field observations and laboratory analyses were used in the study of the Araz, which is a transboundary river. Taking this into account, in addition to the ecological problems of the river, the analysis also examined perennial water consumption and water levels. Because their analysis is of great importance for water resources management, ecosystem protection, and water management planning. One of the main objectives of the study is to investigate the impact of existing reservoirs on the river system. The methodological basis was the analysis of scientific literature, water quality indicators, and international legal documents. The results show that the ecological situation in the Araz has deteriorated in recent years, with pollution levels increasing and biodiversity in the river decreasing. Although the reservoirs located along the river’s flow (Arpachay, Mil-Mughan, Khudafarin and Giz Galasy) play an important role in water resource management, they have negative impacts on ecosystems. International cooperation in addressing the problem has been unsatisfactory, and there are serious coordination problems among countries in the region regarding the joint use of the river. The research concludes that strengthening regional cooperation, improving legal frameworks, and scientifically based ecosystem management are necessary conditions for the sustainable use and protection of the Araz River.