Window curtain rod assemblies that include a telescoping rod and two alignment bracket assemblies, each including a support arm and an alignment mounting bracket are disclosed. Each alignment bracket assembly includes a horizontal portion that extends in a horizontal direction parallel with an axial direction of the telescoping curtain rod away from the vertical edges of a window frame to allow the alignment bracket assembly to be mounted adjacent to the vertical edges of the window frame, while still allowing the curtain to extend beyond the vertical edge of the window frame. The support arms may include a first substantially cylindrical end and a second end. The alignment mounting bracket may be attached to the second end, and include a vertical guide leg having a vertical guide edge and horizontal guide edge.