The review outlines the experimental studies that have led to the current understanding at a molecular level of the protective role exerted by Dps proteins under stress conditions. After a brief description of the structural signatures and of the ferroxidase activity, which confers to all Dps proteins the capacity to decrease the hydroxyl radical induced DNA damage, the interaction of some family members with DNA is analysed. Special emphasis is given to the Dps structural elements that render the interaction with DNA possible and to the consequences that complex formation has on nucleoid organization and microbial survival.