Abstract <p>The paper discusses why the intrasecular fluctuations in the level of the great lakes of Eurasia differ so much. The paper addresses both the phenomenon of the lowest position of the Caspian water level over the entire the history of observations and the problems of regulation of the Lake Baikal level that have been discussed over the past few decades. The paper substantiates the causes for a significant difference in the intrasecular fluctuations and multidirectional trends in the level of Ladoga and Onego lakes belonging to a single water system. Discussed are the specific features in the variability of the level of the great Eurasian lakes amid the global climate warming, mechanisms of the lake level variability, and possible ways to forecast long-term changes in lake water level.</p>