[en] Advanced intermetallic materials, such as refractory silicides, exhibit high melting points, high stiffness, low densities, and good strength retention at elevated temperatures. Further, some of these silicides are in equilibrium with terminal refractory solid solution (beta) phases, and therefore, offer the potential for ductile phase toughening. Studies were conducted to elucidate the compressive creep behavior of monolithic Nb₅Si₃ and to generate the constitutive creep law. This, in turn, is required for modeling the creep behavior of the Nb/Nb₅Si₃ two-phase system. Nb₅Si₃ has the ordered tetragonal structure with 32 atoms/cell in both its allotropic forms: αNb₅Si₃ (D8_l Cr₅Si₃-type; a ∼ 0.656 nm; c = 1.187 nm) and βNb₅Si₃ (D8_m W₅Si₃-type; a = 1.000 nm; c = 0.507 nm). αNb₅Si₃ is stable below 1,935 C, while βNb₅Si₃ is stable above 1,645 C. The large lattice parameters as well as the large number of atoms in the unit cell suggest that dislocation creep is unlikely to occur in Nb₅Si₃, because large Burgers vectors and complex dislocation core structures are expected in this material