The effect of C-60 fullerene on the mechanical properties of epoxy resins has been investigated. It is found that this filler affects the tensile modulus and tensile strength of epoxy compositions only slightly, but their impact strength at a 0.01-0.12 wt.% content of C-60 increases by about 100-200%. A molecular mechanism of the toughening effect of C-60 on epoxy resins is suggested.