Resistance to various classes of antimicrobial agents has been encountered in many bacteria of medical and veterinary relevance. Particular attention has been paid to zoonotic bacteria such as Salmonella. Over the years, various studies have reported the presence of genes and mutations conferring resistance to antimicrobial agents in Salmonella isolates. This review is intended to provide an update on what is currently known about the genetic basis of antimicrobial resistance in Salmonella.