Behçet’s disease (BD) is a complex disease characterized by recurrent episodes of oral and genital ulcers and inflammatory lesions in a variable number of vessels throughout the body which lead to significant organ involvement. This condition, given its low prevalence, is classified as a rare systemic vasculitis. Although its etiology remains unclear, it is known that it is a multifactorial and immune-mediated disease in which imbalances of the immune response, triggered by environmental factors in genetically predisposed individuals, may be the underlying mechanisms of the disease. Throughout this chapter, we will review the current knowledge of the genetic component identified in this disorder. Firstly, we will focus on the HLA region which harbors the strongest known susceptibility factors for this disease. Additionally, we will review the available data in non-HLA regions, highlighting the confirmed risk loci and summarizing those that are only suggested. Finally, we will provide an overview of the main molecular pathways involved in the development of this pathology.