The copper(II) complex [Cu 2 (mal) 2 (H 2 O) 2 (4,4%-bpy)] (1) (H 2 mal=malonic acid and 4,4%-bpy= 4,4%-bipyridine) has been prepared and its structure determined by single crystal X-diffraction methods. Compound 1 has a two-dimensional square grid network structure. The square grids are stacked parallel but in a staggered manner on each other along the c-axis, with an interlayer separation of 3.850(1) A , . Each layer contains a large cavity of 15.784(1) × 15.784(1) A , with each edge shared by one malonate group and one 4,4%-bpy ligand and a small planar square of 4.644(1) ×4.644(1) A , with Cu(II) ions and malonate groups at each corner and side, respectively. Each copper atom is in a distorted square-pyramidal surrounding with three carboxylateoxygen atoms from two malonate groups and one nitrogen atom from a 4,4%-bpy ligand building the equatorial plane and a water molecule in the axial position. Each 4,4%-bpy molecule exhibits the bis-monodentate bridging mode whereas the malonate simultaneously adopts the bidentate (at one copper atom) and monodentate (at the adjacent copper atom) coordination modes. The bridging carboxylato exhibits the anti-syn coordination mode. The magnetic properties of 1 have been investigated in the temperature range 1.9-300 K and they correspond to a dominant ferromagnetic coupling through bridging malonato within the small square defined by four copper(II) ions (J= +12.4(1) cm -1 ) and much weaker intrasheet antiferromagnetic coupling between copper(II) ions through bridging 4,4%-bpy ( j eff = -0.052(1) cm -1 ).