Reaction of U(BH4)3·nTHF with Cp*2Th(PPh2)2 in a THF/toluene solution containing NaCl resulted in isolation of the novel tetrahydroborate complex [Na(THF)6][Cp*U(BH4)3]2, Cp*=C5Me5. The complex crystallizes in the space group P1 with cell parameters of a=11.110(3), b=15.140(3), c= 17.856(3) Å, α=88.27(1), β=74.49(2) and γ= 85.42(2)o, Z=2 and Dcalc=1.49 g/cm3. The unit cell contains two crystallographically independent uranium atoms in general positions, each coordinated by three tridentate, hydrogen-bridged BH4− groups and one η5-pentamethylcyclopentadienyl ligand. Two Na(THF)6+ cations, which occupy centers of crystallographic symmetry, complete the structure. Metrical parameters are not significantly different between the two independent uranium centers (av. UB distances 2.61 Å) or the two independent sodium containing cations. Crystallographically independent Cp*U(BH4)3 moieties pack to form two separate chains parallel to the crystallographic a axis. The stoichiometry and accompanying black color for the crystal suggest a mixed-valent charge transfer compound for which the average uranium oxidation state is 3.5. An unexpected Cp* transfer from thorium to uranium is also noted in the reaction chemistry.