Abstract: A thermoplastic molded sheath for a knife grips the knife tightly to prevent accidental loss or withdrawal. The security of such grip is sufficient to enable the knife to be carried in the sheath in an inverted position upon the body of the wearer. The sheath is made by thermoforming a rigid yet resilient thermoplastic about a knife blade having the exact dimensions of the blade which is to be carried within the sheath. The thermoformed sheath may be attached at its bottom to a pocket-sized semirigid pocket-retaining clip, which clip, when inserted into a pocket, supports the sheath in an inverted position with the blade of the knife extending upwardly and the hilt of the knife in a convenient position for drawing from the sheath. The combination of the orientation of the sheath and the pocket retaining clip places a minimum stress upon a pocket and is comfortable to wear.