Storage rings have been employed over three decades in various kinds of nuclear and atomic physics experiments with highly charged ions. Storage ring operation and precision physics experiments benefit from the availability of beam cooling which is common to nearly all facilities. The basic aspects of the storage ring components and the operation of the ring in various ion-optical modes as well as the achievable beam conditions are described. Ion storage rings offer unparalleled capabilities for high precision experiments with stable and radioactive beams. The versatile techniques and methods for beam manipulations allow for preparing beams of highest quality at any energy of interest. The rings are therefore part of the experiment . Recent experiments conducted in a wide energy range and with various experimental installations are discussed. An overview of active and planned facilities, new experimental set-ups and proposed physics experiments completes this review.