Background: Endometriosis is a chronic disease affecting women of reproductive age. Adolescent onset of symptoms is common. Macrophage migration inhibitory factor (MIF) is one of non-invasive blood biomarker that was found in endometriosis. Aim of the work: to evaluate the value of macrophage MIF in peripheral blood of women with and without endometriosis as a non-invasive early diagnostic method and correlate its level to the stage of the disease. Patient and methods: This observational case-control study was conducted in El-Hussein Hospital, Al-Azhar University, Cairo and private clinics. The study was approved by the local research ethics committee. During the period from May 2016 till July 2018. Results: Both groups were comparable as regard the incidence of infertility and the presence of chronic pelvic pain. The infertility was equal in both groups; it affected 96% of patients and control groups. The chronic pelvic pain was symmetrically present in both groups; it affected 70% of endometriosis and the control group. The level of MIF was 10.03±1.78 pg/ml in patients with endometriosis and 4.82±1.78 pg/ml in control group with significant P value (P <0.001). In our study, the level of MIF differed according to the stage of endometriosis, in stage I, it was 8.6±0.2 pg/ml, in stage II, it was 10.1±0.1 pg/ml, in stage III, it was 11.3±0.2 pg/ml and in stage IV, it was 14+0.0 pg/ml. Conclusion: MIF factor is a promising marker not only for noninvasive diagnosis of endometriosis but as a target for therapy also