Bacterial diseases have had an enormous impact on human health and continue to be a major focus in modern medicine. The most widespread class of human antibacterials is the b-lactams that target the transpeptidase enzymes, which are responsible for cross-linking the peptidoglycan cell wall. There are over 34 FDA-approved b-lactams which together constitute $50 % of all antibiotic prescriptions worldwide (Tahlan K and Jensen SE, J Antibiot (Tokyo) 66:401-410, 2013). However, bacteria have gained resistance mechanisms to overcome all major classes of b-lactam antibiotics to date. In this chapter, we will address the major mechanisms of bacterial resistance to the b-lactams and highlight some of the recent advances in circumventing this resistance.