The new ternary compd. U3Fe4Ge4 was prepd. by melting the pure metals in the stoichiometric ratio. An ingot of large scale domain was obtained by decreasing the temp. from the liq. state down to 1000° over 4 h. Single crystal x-ray diffraction revealed that U3Fe4Ge4 crystallizes with the Gd3Cu4Ge4-type of structure, in the orthorhombic space group Immm (no. 71), Z = 2, with unit-cell parameters at room temp. of, a = 4.090(1) Å, b = 6.639(1) Å and c = 13.702(1) Å, R = 0.031, wR2 = 0.069 [I \textgreater 2σ(I)]. The crystal structure is characterized by 2 U, 1 Fe, and 2 Ge independent crystallog. positions and can be described as resulting from the condensation by face-sharing and edge-sharing of U(1)Ge6 octahedrons, U(2)Ge6 trigonal prisms and Fe(1)Ge4 tetrahedrons. The electronic properties of this new compd. were investigated by elec. resistivity, thermopower, ac and d.c. magnetic susceptibility and 57Fe Mossbauer spectroscopy. U3Fe4Ge4 undergoes a ferromagnetic transition below TC = 17(1) K. The low temp. (4 K) 57Fe Mossbauer spectra can be well fitted using a model with Fe atoms in a paramagnetic state, suggesting that the magnetic ordering originates from the U sublattice alone. [on SciFinder(R)]