A novel two-dimensional (2D) azido-based Cu(II) network, [Cu11(pic)6(N3)16] (1), was prepared using picolinic acid (Hpic) as coligand. Interestingly, 1 is composed of symmetric double azido EO-bridged [Cu(N3)2]n chains linked by [Cu(pic)2] units making a regular ladder with a missing rung. These rung-defected ladders are assembled in a layered structure by long azido-Cu(II) contacts between neighboring [Cu(N3)2]n chains. The magnetic properties of 1 are dominated by significantly strong antiferromagnetic coupling (J/kB = -15.4(2) K) between Cu(II) spins through the double EO azido-bridges along the [Cu(N3)2]n chains.