The anti biotic-group of cephalosporins consisting hundreds of active substances is one of the most frequently used drugs in the human and veterinary practice, as well. Despite the high price, their broad antibacterial spectrum, bactericidal mode of action and large therapeutic index make them widely used substances. The goal of this review is to summarize the most important data about cephalosporins, taking into account their antibacterial spectrum, importance and mechanisms of resistance, adverse effects, pharmacokinetic behaviour and their clinical usage.