Abstract: A security device for tackle boxes and the like which requires little alteration of the tackle box or item being secured thereby for substantially precluding theft of the item. The device comprises a sleeve member open at one end and closed at the opposite end, with the closed end being secured to the bottom of a boat, floor or other substantially permanent support structure for receiving the tackle box, or the like, thereon. The sleeve member extends through an aperture provided in the bottom of the tackle box, and a pair of aligned bores are provided in the sidewalls of the sleeve for removably receiving a padlock member therethrough. The bolts, or the like, securing the sleeve to the support structure are concealed by the tackle box and the padlock, which is disposed within the tackle box, precludes removal of the tackle box from the sleeve as long as the padlock is in the locked position.