Beta-lactam antibiotics are a group of antibiotics that hold β-lactam ring in molecular structure. These are widely used antibiotics mainly in developing countries against bacterial infections. β-lactam group of antibiotics, originally found in fungi Penicillium notatum inhibit cell wall biosynthesis in bacteria especially Gram-positive organisms. The development of new derivatives of β-lactam class- carbapenem, cephalosporins, cephamycin, monobactam are efficient against bacterial species which have developed resistance mechanisms. This review will walk readers through the discovery and golden age of β-lactam, mechanism of action as broad-spectrum antibiotic, expansion of beta-lactam derivatives, β-lactamase inhibitors to antibiotic resistance in β-lactams. © 2020 by Nova Science Publishers, Inc.