The present invention relates to markers of endometriosis which are differentially expressed in the endometrial cells of females with endometriosis compared to endometriosis-free females. The invention also relates to methods for determining likelihood of endometriosis in female subjects, to methods for grading endometriosis in females suffering from endometriosis and to methods for treating this disease. The invention is also concerned with polynucleotides, probes, primers and kits useful for reducing into practice the above-mentioned methods which are more rapid, non invasive, much less complicated and much less costly than laparoscopy.