Introduction: Endometriosis is a sex hormone-dependent and successively progressing gynecological disease, characterized by the presence of endometrial tissue outside the uterus. The etiology of endometriosis is known to be multifactorial, and its growth depends on immunological, hormonal, genetic and environmental factors. Angiogenesis plays a key role in implantation and growth of endometriotic lesions, as well as in adhesion formation. Physiologically angiogenesis is responsible for neoangiogenesis and recruitment of new capillaries from the already existing capillaries. It is well-documented that altered angiogenesis provokes improper follicular maturation, infertility, recurrent miscarriages, ovarian hyperstimulation syndrome, and carcinogenesis. Factors stimulating angionesis include angiogenin, vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF). Objectives: The aim of the study was to analyze angiogenic factor concentration (angiogenin, VEGF, FGF) in blood serum and peritoneal fluid in patients with diagnosed endometriosis and idiopathic infertility. Material and methods: A total of 39 patients were recruited for the study, including 19 patients (study group) diagnosed with endometriosis during the laparoscopic procedure and 20 patients (control group) with idiopathic infertility and no morphologic changes within the pelvis revealed during the laparoscopic procedure. All patients underwent laparoscopy during the follicular phase of the menstrual cycle. Vein blood sample was obtained before the procedure and during laparoscopy the entire peritoneal fluid was aspirated for further measurement of VEGF, FGF and angiogenin concentrations. Results: Angiogenin concentration in peritoneal fluid was statistically higher in patient with idiopathic infertility in comparison to endometriosis (p<0.05). Higher angiogenin concentration was detected also in blood serum of patients with idiopathic infertility as compared to patients with endometriosis, but no statistical significance was found. VEGF and FGF concentration in blood serum and peritoneal fluid was similar in both groups (p>0.05). There were no significant differences between serum and peritoneal fluid in case of VEGF, FGF and angiogenin in any of the groups. Conclusions: Angiogenic factors concentration (VEGF, FGF, agiogenin) in the peritoneal fluid and blood serum during the follicular phase of the menstrual cycle is not a diagnostic criterion for endometriosis.