Abstract: A tamper resistant closure for screw top and other containers is provided which resists and visibly discloses attempted tampering. A heat shrinkable plastic sleeve including at least one row of longitudinal mechanical weakness, such as a line of perforations, snuggly surrounds both the screw cap and a portion of the neck of the associated container. Sharp protruding teeth integral to the covered portion of the container neck interfere with the longitudinal weak areas when the shrunk sleeving is forcibly rotated during an attempted tampering, causing a portion of the plastic material to rupture and indicating tampering. By providing a second row of longitudinal weakness, such as a second closely spaced parallel line of perforations, a tear-away portion results whereby the features which provide indication of tampering also provide a convenient means for desired removal of the protective sleeve by the intended user.