The molecular and crystal structure of the compound Bis-[1H-indole-3-ethylene-3'-methoxy-salicylaldimine]copper(II) monohydrate has been determined. This compound crystallizes in the monoclinic system, C2/c space group, Ζ = 4, cell dimensions a = 18.657(2), b = 7.194(1), c = 23.932(1)A, β = 91.92(2)°, V = 3210(1) A 3 , D x = 1.41 Mg/m 3 , F(000) = 1396. The structure has been refined to R = 0.043 and wR = 0.045 for 3 643 independent observed reflections. The structure consists of one molecule of [QeH^^C^hCu and a water molecule not-coordinated to metal. The geometry around the copper atom is planar with the metal lying on a centre of symmetry. The water molecule plays an important role in the formation of inter molecular hydrogen bonding (OW... N(2) 2.900(9) and OW...O(21) (-x+l, -y, -z) 2.848(3) A).