Geometries associated with relative stabilities, energy gaps, and polarities of W-doped germanium clusters have been investigated systematically by using density functional theory. The threshold size for the endohedral coordination and the critical size of W-encapsulated Ge-n structures emerge as, respectively, n = 8 and n = 12, while the fullerene-like W@Ge-n clusters appears at n = 14. The evaluated relative stabilities in term of the calculated fragmentation energies reveal that the fullerene-like W@Ge-14 and W@Ge-16 structures as well as the hexagonal prism WGe12 have enhanced stabilities over their neighboring clusters. Furthermore, the calculated polarities of the W@Ge-n reveal that the bicapped tetragonal antiprism WGe10 is a polar molecule while the hexagonal prism WGe12 is a nonpolar molecule. Moreover, the recorded natural populations show that the charges transfer from the germanium framework to the W atom. Additionally, the WGe12 cluster with large highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap, large fragmentation energy, and large binding energy is supposed to be suitable as a building block of assembly cluster material. It should be pointed out that the remarkable features of W@Ge-n clusters above are distinctly different from those of transition metal (TM) doped Ge-n (TM = Cu and Ni) clusters, indicating that the growth pattern of the TMGen depends on the kind of doped TM impurity.