The invention provides a printed circuit board and a method for fabricating the same. The printed circuit board includes a core substrate having a first surface and an opposite second surface. A first through hole and a second through hole are formed through a portion of the core substrate, respectively from the first surface and second surfaces, wherein the first and second through holes are laminated vertically and connect to each other. A first guide rail and a second guide rail are, respectively, formed through a portion of the core substrate and connected to the second through hole, so that a fluid flows sequentially from an outside of the printed circuit board through the first guide rail, the second through hole and the second guide rail, to the outside of the printed circuit board.