Medicinal plants are rich in bioactive compounds derived from the secondary metabolism that characterizes these plants. These secondary metabolites showed several in vitro and in vivo pharmacological properties such as antimicrobial, antioxidant and anticancer effects. Several studies have focused on anti-inflammatory and immunomodulatory properties of medicinal plants and their bioactive compounds. These substances have enormous immunomodulatory anti-inflammatory effects; they can suppress inflammatory factors, potentiate the immune response and regulate the differentiation of immune cells. The mechanistic insights of these molecules are very diverse and include the targeting of immune system receptors, the interference with signaling pathways and deregulation of genes expression. Secondary metabolites activate the expression of several cytokines such as IL-2 and IL-12 to modulate immune response, and decrease the expression of some transcriptional factors such as Nf-KB to suppress inflammatory process.