Endometriosis is a complex, puzzling disease in women of reproductive age. The exact cause of the disease is unknown; however, different genetic and environmental factors contribute to the evolution of the disorder. Further investigation has led to the discovery of inheritance as a complex genetic trait. Candidate genes were identified to isolate regions of genes that affect disease risk. Additional linkage studies have been performed to map specific genes along the entire genome. Recent advances to determine the genetic component of endometriosis include genome-wide association studies. This chapter focuses on different approaches to identify the genetic links of endometriosis and its pathogenesis.