The chronic receipt of renin-angiotensin-aldosterone system (RAAS) inhibitors including angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) have been assumed to be associated with a significant decrease in overall gynecologic cancer risks. This study aimed to investigate the associations of long-term RAAS inhibitors use with gynecologic cancer risks. A large population-based case-control study was conducted from claim databases of Taiwan’s Health and Welfare Data Science Center (2000–2016) and linked with Taiwan Cancer Registry (1979–2016). Each eligible case was matched with four controls using propensity matching score method for age, sex, month, and year of diagnosis. We applied conditional logistic regression with 95% confidence intervals to identify the associations of RAAS inhibitors use with gynecologic cancer risks. The statistical significance threshold was p < 0.05. A total of 97,736 gynecologic cancer cases were identified and matched with 390,944 controls. The adjusted odds ratio for RAAS inhibitors use and overall gynecologic cancer was 0.87 (95% CI: 0.85–0.89). Cervical cancer risk was found to be significantly decreased in the groups aged 20–39 years (aOR: 0.70, 95% CI: 0.58–0.85), 40–64 years (aOR: 0.77, 95% CI: 0.74–0.81), ≥65 years (aOR: 0.87, 95% CI: 0.83–0.91), and overall (aOR: 0.81, 95% CI: 0.79–0.84). Ovarian cancer risk was significantly lower in the groups aged 40–64 years (aOR: 0.76, 95% CI: 0.69–0.82), ≥65 years (aOR: 0.83, 95% CI: 0.75–092), and overall (aOR: 0.79, 95% CI: 0.74–0.84). However, a significantly increased endometrial cancer risk was observed in users aged 20–39 years (aOR: 2.54, 95% CI: 1.79–3.61), 40–64 years (aOR: 1.08, 95% CI: 1.02–1.14), and overall (aOR: 1.06, 95% CI: 1.01–1.11). There were significantly reduced risks of gynecologic cancers with ACEIs users in the groups aged 40–64 years (aOR: 0.88, 95% CI: 0.84–0.91), ≥65 years (aOR: 0.87, 95% CI: 0.83–0.90), and overall (aOR: 0.88, 95% CI: 0.85–0.80), and ARBs users aged 40-64 years (aOR: 0.91, 95% CI: 0.86–0.95). Our case-control study demonstrated that RAAS inhibitors use was associated with a significant decrease in overall gynecologic cancer risks. RAAS inhibitors exposure had lower associations with cervical and ovarian cancer risks, and increased endometrial cancer risk. ACEIs/ARBs use was found to have a preventive effect against gynecologic cancers. Future clinical research is needed to establish causality.