Hypothesis/Introduction: The objective of this article is to investigate the effect of renin-angiotensin system inhibitors (RASIs) on intact parathyroid hormone (iPTH) levels in continuous ambulatory peritoneal dialysis (CAPD) patients. Materials and methods: All patients were divided into RASI-treated and non-treated groups. The relationships between the iPTH levels in CAPD patients and the clinical parameters and medication use were analyzed via linear regression. Results: A total of 149 CAPD patients were included in this study. The average iPTH level of the entire group was 189.4 pg/ml (range, 102.8-373.4 pg/ml). There were 79 (53.0%) and 70 (47.0%) cases in the RASI-treated and non-treated groups, respectively, with average iPTH levels of 139.0 pg/ml (range, 91.6-258.4 pg/ml) and 253.0 pg/ml (range, 134.3-467.2 pg/ml), respectively; this difference was statistically significant (p = 0.001). Multilinear regression analysis showed that age, dialysis vintage, serum phosphatemia, ALP, Hb and RASI use were independent factors that were associated with iPTH level. Conclusion: RASI use may be associated with a lower iPTH level in CAPD patients, although the underlying mechanism requires further study.