Background: There is some evidence suggesting an interaction between the renin-angiotensin-aldosterone system (RAAS) and parathyroid hormone (PTH). Recently, the number of patients who have been diagnosed as asymptomatic hyperparathyroidism among patients with primary hyperparathyroidism (PHPT) has been increasing steadily. Although there are many studies on cardiovascular outcomes in primary hyperparathyroidism, there is not enough data on cardiovascular outcomes in patients with asymptomatic hyperparathyroidism yet. Objective: Our objective was to investigate plasma renin levels and aldosterone concentrations in patients with asymptomatic PHPT. Study design: 32 patients with asymptomatic PHPT and 22 healthy control subjects were recruited for this study. Materials and methods: The levels of renin, aldosterone concentration, PTH, calcium, phosphorus, creatinine, and creatinine clearance were investigated. Results: Median PTH and calcium levels were higher and phosphorus levels were lower in patients with asymptomatic PHPT than control group (p = 0.0001, p = 0.0001, p = 0.0001). There were no statistically significant differences in terms of plasma renin levels (5.9 (3.3 - 9.0) vs. 5.0 (1.8 - 14.5) mU/L, p = 0.62) and aldosterone concentrations (95.0 (52.3 - 132.4) vs. 105.9 (93.2 - 206.5) pg/mL, p = 0.08) between the groups. Also, there were no correlations between calcium, PTH levels and renin levels and aldosterone concentrations (p > 0.05). Conclusion: Our results suggest no major alterations in the RAAS in patients with asymptomatic PHPT.