Background: Endometriosis is a common benign gynecological condition classically defined as the presence of endometrial glands and stoma in ectopic sites outside the uterus. Aim of the study is to assess pain of women with endometriosis. Design: A descriptive study design was used.  Setting: The study was conducted at Benha University Hospital, in IVF unit, Obstetrics & Gynecology Department divided to 2 subunits, these units concerned with Obstetrics &Gynecological diseases and operations and outpatient clinic. Sample Size: The study was conducted for 100 women had endometriosis pain. Sample type: Convenient sample technique was used to select the sample for the study. Tools: Two tools of data collections were used; a structured interview questionnaire and Andrea Mankosk's Pain Scale. Results: The results pointed out that the percentage distribution of women  according to their Andrea Mankoski Pain Scale showed that 29% of the studied women  had a mild level of Andrea Mankoski Pain Scale,  36%  of them had moderate and 35% of them had a severe. According to site of pain, It  showed that  down the pelvis (81%), lower back (56%), legs (22%), the ovaries (50%) and continuous headache (31%) of where is the pain, and according to type of pain, It showed that the burning (22%), stab (6%), nibbling (8%), sharp (9%), painful (89%) and pressure (59%) of types of pain. Conclusion: The present study findings concluded  that the majority of women had negative knowledge regarding endometriosis pain. Recommendations: Activating the role of maternity health nurse, providing educational program for women to improve their knowledge about endometriosis pain and pain relieve measures.