The dry period of dairy cows is very important for udder health in the subsequent lactation. The majority of intramammary infections occur either at the beginning or at the end of the dry period, because of biological changes happening at this time. Since intramammary infections occurring during the dry period are responsible for many clinical mastitis cases at the beginning of the subsequent lactation, minimising the new intramammary infection rate is of great interest. The aim of this review is to give a résumé of all known risk factors that influence cure and new infection rate. Those risk factors can be differentiated into herd level and quarter level factors. Many studies ascertain the dry cow therapy. It was shown that the use of antibiotic dry cow therapy and internal teat sealers reduces the new infection rate and increases the cure rate. Referring to management factors, all measures aiming at reducing the infection pressure and the transmission of infection-causing pathogens from cow to cow have a positive effect. Particularly management factors related to hygiene offer great potential.