Abstract: A container closure which indicates the number of times which a container is opened comprises a counting screw cap for a container three members arranged for rotation relative to one another, the first member threadedly engaging the neck of the container, the second member being arranged to be manually grasped for removing the cap from the container, there being provided a lost motion drive between the first and second members so that the second member is enabled to rotate through a predetermined angle in each direction without causing rotation of said first member while rotation of the second member beyond the predetermined angle causes rotation of the first member to screw the latter onto, or remove it from, the neck of the container.