A new procedure developed for the synthesis and crystallization of various zinc(II) fumarate hydrate coordination polymers is described. In the first step, anhydrous Zn(II) fumarate, [Zn(C4H2O4)] (1), is synthesized from Zn(II) acetate and fumaric acid in methanol. Subsequently, this product is used as a starting material for growing small crystals of bis-aqua Zn(II) fumarate, [Zn(H2O)(2)(C4H2O4)] (2), triaqua Zn(II) fumarate monohydrate, [Zn(H2O)(3)(C4H2O4)]H2O (3), tetraaqua Zn(II) fumarate, [Zn(H2O)(4)(C4H2O4)] (4), and tetraaqua Zn(II) fumarate monohydrate, [Zn(H2O)(4)(C4H2O4)]H2O (5). All structures were determined or redetermined by X-ray structure analyses. The hitherto unknown compound 3 exhibits a zig-zag chain structure with five-coordinate Zn(II) ions.