Hypericum perforatum L. (Hypericaceae) is one of the medicinal plants whose value has increased rapidly in recent years. It is especially popular for its use in the treatment of mild and moderate depression, as well as for the treatment of skin diseases, internal and external inflammatory wounds, neurological disorders, and the metabolism-disrupting effects of free radicals. Besides, it shows inhibitory effects against different kinds of microorganisms such as bacteria, fungus, and protozoa. Antimicrobial biofilms generated by the plant are its most potent output, unlike its essential oil which does not have much value in itself as much as its ingredients that can be converted into more valuable products. Its usage as a folk remedy has a wide application area in various cultures. It is thought that compiling studies on various aspects of this plant will benefit future studies. The present paper reports on studies on the antibacterial, antioxidant, and therapeutic properties of Hypericum perforatum, as well as on the composition of its essential oil.