The present invention anti-rotational fastener for an automotive vehicle comprises a cap portion suitable for attachment to an electrical apparatus and a barbed shaft. The shaft has a pair of broad sides and a pair of thin sides, all of which extend perpendicularly downward from the cap portion for attachment to an automotive vehicle body panel. This difference in shaft side dimensions corresponds to an elongated slot cut within the vehicle body panel, thereby preventing rotation of the fastener and, in turn, the electrical apparatus. Furthermore, an upper portion of the shaft broad sides has a pair of wings oppositely extending outward therefrom in order to mechanically stabilize the fastener against rotational movements in vertical planes which would otherwise tend to loosen the fastener. In an alternative embodiment, the anti-rotational fastener of the present invention can be used to retain and prevent rotation of a portion of a wire harness.