A needle safety assembly comprising a needle and a protective cover for the needle, wherein the needle is attached to a needle hub having wings on opposite sides which can be moved relative to the protective cover from a position of use where the tip of the needle is outside of the protective cover into a retracted position in which the needle is fully received in the protective cover. The protective cover is of generally tubular shape having two opposite axial slots extending from a distal end of the protective cover towards a tubular base portion of the protective cover. The slots are adapted to receive the wings when the needle hub moves into the protective cover. Also provided is a locking mechanism adapted to secure the needle hub inside the protective cover when the needle hub is retracted.