Background: Premenstrual syndrome (PMS) has been associated with dysregulation of the renin–angiotensin–aldosterone system (RAAS), a pathway also implicated in hypertension. Evaluation of blood pressure (BP) patterns in adolescents with PMS may therefore clarify shared neuroendocrine and vascular mechanisms. This study aimed to compare BP profiles in adolescents with and without PMS and to assess phase-specific BP variations across the menstrual cycle.Methods: Adolescents aged 12–18 years with regular menstrual cycles for at least three months were enrolled. PMS was assessed using the Gencdogan Premenstrual Syndrome Scale (PMSS). Office BP measurements (OBPM), 7-day home BP monitoring (HBPM), and 24-hour ambulatory BP monitoring (ABPM) were conducted during the follicular and luteal phases.Results: The study included 31 adolescents with PMS (mean age 15.61 ± 1.42 years) and 21 without PMS (mean age 14.82 ± 1.40 years). PMS (+) and PMS (−) groups were comparable regarding office BP, 7-day HBPM, and 24-hour ABPM in both phases. Within the PMS group, 7-day HBPM demonstrated significantly higher morning and mean systolic BP during the luteal phase compared with the follicular phase (p = 0.001 and p = 0.006, respectively). Conversely, 24-hour ABPM showed lower 24-hour and daytime diastolic BP (p = 0.029 and p = 0.019, respectively) and higher pulse pressure (p = 0.018) during the luteal phase.Conclusion: Elevated luteal-phase systolic BP in adolescents with PMS may reflect RAAS-related mechanisms, whereas reduced diastolic BP may be attributable to estrogen- and progesterone-mediated vascular effects. Longitudinal studies are needed to determine the persistence and cardiovascular implications of these BP patterns.