The increasing prevalence of persistent biofilm infections, such as wound infections, chronic lung infections or medical device- related infections, which usually tolerate conventional antibiotic treatment, calls for the development of new therapeutic strategies. To date, antimicrobial peptides (AMPs) are considered as promising agents in the fight against multidrug-resistant bacterial biofilm infections, since many of them have been shown to prevent biofilm formation or even kill preexisting, mature biofilms of several Gram-positive and Gram-negative bacteria in addition to their bactericidal actions to planktonic cells. In this mini-review, we summarize in vitro and in vivo antibiofilm properties of natural and synthetic cationic AMPs against clinically relevant bacterial pathogens. Furthermore, the benefits and challenges in the use of AMPs for the medical treatment of bacterial biofilm infections are discussed.