Drying up procedures of udders in dairy cows, physiological mechanisms, effects of dry period on milk production and mastitis, protection of involuted udder against mastitis (infections) and application of antibiotics for prophylactic purposes before the dry period were reviewed. In addition, effects of such a procedure on the teats, properties of antibiotics to use in the dry period, various protocols for periodical applications and antibiotics residues in milk and colostrum were comprehensively discussed in this review.