The crystal structure of U 3 Ga 2 Ge 3 has been investigated by means of neutron powder diffractometry in the range from 1.5 to 100 K. Full matrix full profile refinements of the nuclear structure at 100 K revealed a new structure type with almost fully ordered distribution of Ga and Ge atoms in the 8c sites of space group I4. The new U 3 Ga 2 Ge 3 type is a low symmetry derivative of the ordered antitype-Cr 5 B 3 (I4/mcm), R I ؍ 0.032, R F ؍ 0.030. From model refinements, eventual interstitial nonmetal occupation in the metal octahedra U 1 Ge 1 Ge 2 Ga 2 or U 2 Ge 2 Ga 2 or in metal tetrahedra Ge 2 Ga 2 is ruled out. At temperatures lower than T c ؍ 90 K uranium atoms order ferromagnetically as monitored by the intensity of the magnetic reflection M I (011) . Due to the observation of the M (011) reflection, the magnetic spin structure is consistent with the symmetry of the noncentrosymmetric space group I422. The lower symmetry invokes a splitting of the 4a sites of the parent Cr 5 B 3 type (I4/mcm) into two twofold uranium sites 2a and 2b of I422. Besides the uranium atoms in 8j ( U ؍ 2.57 B ), only the uranium atoms in 2a were found to carry a magnetic moment U ؍ 2.45 B . All moments are parallel to the crystallographic a axis. To comply with the symmetry of the Ge/Ga atoms, magnetic and nuclear structure have to be described in space group I4. The reliability values for the 1.5 K diffractogram were: R I ؍ 0.024, R F ؍ 0.019, and R mag ؍ 0.033.