He is most notable for leading the Russian polar expedition of 1900–1902 in search of the legendary Sannikov Land, a phantom island purported to lie off Russia's Arctic coast.

He belonged to the Baltic German noble Toll family and was married to Emmeline "Emmy" Magdalene von Wilcken [et].

Under a peat composed of water mosses covering what he described as "perpetual ice", now known to be permafrost, Baron von Toll found fragments of willow and the bones of post-Neogene mammals, like the shoulder-bone of a saber-toothed tiger.

He also reported having found in a frozen, sandy clay layer and lying on its side, a complete tree of Alnus fruticosa 15 to 20 ft (4.5 to 6 m) in length, including roots, with leaves and cones adhering.

[5] In 1893 Toll led an expedition of the Petersburg Academy of Sciences to the northern parts of Yakutia and explored the region between the lower reaches of the Lena and Khatanga Rivers.

Owing to the difficulties of the expedition and his hard work, the Russian Academy of Sciences awarded Eduard v. Toll with the N.M. Przhevalsky Large Silver Medal.

The ship Zarya attempted to reach Bennett Island to evacuate Toll's party but was unable to do so because of severe ice conditions.

They did not find the lost explorers but they found the diaries and the collections of the Zarya expedition, which shed light on the tragic fate of Baron Eduard von Toll and of his companions.