A PCI card fastening device for fastening a PCI card to a chassis includes a latching plate fixed to the PCI card, a latching element slidably fixed to the chassis and a locking element. The latching element includes a latching hole and a latching portion. The locking element is rotatably fixed to the latching element, the locking element includes a pressing board and a hook, the hook includes a securing block. The latching plate is latched to the latching portion, the securing block is latched in the latching hole to latch the locking element to the latching element. After the securing block is released from the latching hole, the pressing board moves away from the latching element to release the latching plate between the pressing arm and the latching element.