Objective: It is a well known fact that endometriosis is linked with apoptosis, extracellular matrix formation, and angiogenesis. In this study, the authors aim to investigate the relation between the extent of endometriosis and vascular endothelial growth factor (VEGF). Materials and Methods: Twenty-one patients who received laparoscopic intervention due to endometriosis constituted the patient group, whereas 19 patients who were operated due to extra-endometrial benign cyst were included in the control group. Following the laparoscopic pelvic assessment, peripheral blood samples and two cc of free peritoneal fluid from the Douglas pouch were obtained simultaneously. The samples were studied with regards to VEGF level via solid phase sandwich enzyme-linked immunosorbent assay (ELISA) method. Results: In the patient group, eight cases were diagnosed with Stages I and II endometriosis, while 13 cases were diagnosed with Stages III and IV endometriosis. Among the Stage I and II cases, serum VEGF levels were statistically significantly higher, as compared to the Stage III and IV cases, as well as the control group. Discussion: In conclusion, the authors found a relationship between elevated serum VEGF levels and early stage endometriosis.