Objectives: This study aimed to investigate the relationships between inflammatory, oxidative, and endothelial biomarkers—specifically serum endocan, procalcitonin, malondialdehyde and total antioxidant status —and without and with primary dysmenorrhea. Desing: Prospective cohort study. Setting: Women aged 18–30 years with moderate to severe primary dysmenorrhea and healthy controls without dysmenorrhea were enrolled. Population or Sample: A total of 42 women with primary dysmenorrhea and 42 healthy controls were included in the study. Methods: All participants underwent pelvic ultrasonography on the first day of menstruation. Pain severity was assessed using the visual analog scale. Venous blood samples were collected on the same day, and serum endocan, procalcitonin, malondialdehyde, and total antioxidant status levels were measured using ELISA. Clinical and laboratory variables were compared between groups, and univariate binary logistic regression analysis was performed to identify factors associated with dysmenorrhea. Main Outcome Measures: Serum MDA and TAS levels of the groups Results: Women with primary dysmenorrhea had significantly higher serum procalcitonin and endocan levels compared with controls (p < 0.05). No significant differences were observed in MDA or TAS levels between groups. Univariate logistic regression analysis revealed that serum procalcitonin, endocan, menstrual cycle length, follicle-stimulating hormone, and dehydroepiandrosterone sulfate were significantly associated with the presence of dysmenorrhea. TAS levels showed an inverse correlation with pain severity.