Neodymium ruthenium disilicide, M(r) = 301.48, monoclinic, mP8, P2(1)/m - e4 (No. 11), a = 4.4620 (6), b = 4.0451 (6), c = 8.242 (2) angstrom, beta = 102.23 (1)-degrees, V = 145.39 (5) angstrom 3, Z = 2, D(x) = 6.887 Mg m-3, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 22.065 mm-1, F(000) = 264, T = 293 K, wR = 0.040 for 459 contributing unique reflections. The structure is isopointal with TmLi1-xGe2 (x = 0.5), both being distortion variants of the orthorhombic CeNiSi2-type structure. Opposite to what is observed for TmLi0.5Ge2, the distortions in NdRuSi2 are such that all non-metal atoms take part in infinite zigzag chains. Ru-Ru distances of 3.08 angstrom exist.