Sunflower plants show pronounced allelopathic traits and represent a suitable base for potential scientific research work. Understanding and exploiting precisely of that potential could greatly reduce the use of chemical products for plant protection that are intensively used in the production technology of this crop. Today, a big effort is made in sunflower breeding in order to produce the resistance to the economically most important pathogens, which are in most cases phytopathogenic fungi and parasitic weeds such as broomrape. Since sunflower is an increasingly popular crop within farmer fields in the Republic of Serbia, an overview of so far known, passive and active defense mechanisms, that are key for the crop resistance creating, is given. The study also describes in detail, the interactions among the most harmful fungal pathogens and sunflower plants, the expression of genes caused by their attack, and the production of metabolites that are crucial for the induced defense formation.