Background: Endometriosis is benign gynecological disorder that affects women during reproductive age and negatively affects women lives. Aim of the study: To evaluate level of knowledge, pain and lifestyle among women with endometriosis. Study Design: Descriptive design. Setting: The study was carried out at gynecological outpatient clinic of Zagazig University hospitals as it covers a wide range of population with different characteristics with high flow rate. Study sample: A purposive sample of 132 women was included in the study. Tools of data collection: Four tools were used: A structured interview questionnaire, knowledge assessment questionnaire, pain assessment questionnaire and lifestyle assessment questionnaire. Results: A higher percentage of women correctly knew symptoms and goal of treatment of endometriosis. Dysmenorrhea and pelvic pain were the main types of pain in the majority of women. The most consumed diet by almost half of them was red meat and beef, low physical activity was reported by less than half of them and the majority of them had poor sleep quality. Conclusion: Half of women had poor level of knowledge and small percentage of them had good level of knowledge. Half of women had severe pain, less than one fourth of them had moderate pain, and one fourth of them had mild pain while small percentage of them had no pain. The total life style was unhealthy in the majority of women and healthy in almost one fourth of them. Recommendations: It is very important to raise awareness and enhance women knowledge regarding endometriosis through mass media, the presence of educator nurse who provides knowledge either by provision of written or oral instructional guidelines in а simple Arabic language to all women attending gynecological outpatient clinics.