Native metals grains are highly resistant during exogenous processes, which allows to use cosmogenic 3He in them to determine the timescales of their storage at the Earth’s surface. Herein we present the results of exposure dating of PGM grains from the Kondyor-Uorgalan placers associated with the alkaline-ultramafic massif Kondyor (Khabarovsk district) and from a number of placers in the Middle Urals characterized by different distances from their sources – Svetloborskiy and Kamenushensky clinopyroxenite-dunite massifs. It has been shown that the duration that grains can spend at the Earth's surface can reach tens of millions of years.