In the past decades, finding new antimicrobials has become one of the most important issues of modern society. Increasing and uncontrolled antimicrobial resistance has led to an alternative in the form of plant matrices as a source of antimicrobial secondary metabolites. Plant secondary metabolites encompass a diverse array of compounds synthesized by plants, which serve essential functions in their growth, development, and interactions with the environment. Unlike primary metabolites involved in core physiological processes, plant secondary metabolites contribute to adaptive and defensive mechanisms. An intriguing characteristic of plant secondary metabolites lies in their bioactivity, particularly their antimicrobial properties. These compounds equip plants with defense mechanisms against a broad spectrum of bacteria and fungi. Their antimicrobial potential arises from the capacity to delay or inhibit the growth, development, and survival of microbial cells. The antimicrobial potential of plant secondary metabolites stems from their diverse chemical structures and modes of action. Given the multifaceted antimicrobial activities displayed by plant secondary metabolites, significant attention has been directed toward their exploration in medicine, agriculture, and food preservation. These compounds are investigated as natural alternatives to conventional antimicrobials, aiming to address concerns surrounding drug resistance and foster sustainable solutions. However, it is essential to acknowledge that the antimicrobial potential of plant secondary metabolites is contingent upon various factors, including compound concentration, target microorganisms, and environmental conditions. Ongoing research endeavors seek to unravel the identities of these bioactive compounds, elucidate underlying mechanisms of action, and explore their potential applications across diverse scientific domains and industrial sectors. Therefore, this chapter offers review of antibacterial and antifungal potentials of plant secondary metabolites which are divided into four main groups: (i) terpenes; (ii) phenolic compounds; (iii) hormones, quinones, xanthones, and isocoumarins; and (iv) flavonoids enabling essential information about chemical profile, antimicrobial potential as well as mechanisms of action.