Endometriosis is a common gynaecological disorder of unknown aetiology and accounts for infertility and pelvic pain in 10-15% of women of reproductive age. Angiogenesis is the formation of new capillaries from pre-existing vessels and it is now apparent that this process plays an important role in the pathogenesis of endometriosis. Erythropoietin is an important regulator of erythropoiesis and stimulates the proliferation of early erythroid precursors and the differentiation of late erythroid precursors of the erythroid lineage. Several studies have demonstrated the angiogenic potential of erythropoeitin EPO.