Two Schiff-base copper (II) complexes, bis (Nn-butyl-5-chlorosalicylaldiminato) copper (II)(1) and bis (Nn-butyl-4-methoxysalicylaldiminato) copper (II)(2), were synthesized and their solid-state structures were determined by X-ray crystallography. Complex 1 displays a distorted square-planar geometry, while 2 possesses square-planar geometry. Copper (II) complexes 1 and 2 showed strong inhibitory activity against jack bean urease (IC50= 2.7, ...