Background/Objectives: Primary aldosteronism (PA) is associated with a higher cardiovascular disease (CVD) risk than essential hypertension (EH) and is mainly driven by the excess of aldosterone production. Studies suggest a relationship between aldosterone and parathormone (PTH) homeostasis. Excessive PTH levels seem to also be associated with CVD. The impact of PTH levels on CVD in PA patients has not been totally elucidated. We evaluated the associations of PTH levels and hyperparathyroidism with CVD in patients with PA and EH. Methods: A cross-sectional study of a group of 67 patients was carried out, with 35 patients with PA and a control group of 32 patients with EH. We looked at the presence of CVD and data on the factors associated with its presence were collected and analyzed. A binary logistic regression was performed to assess multivariate relationships. Results: PA patients had higher PTH levels compared to the EH group (64 ± 42 vs. 39 ± 13 pg/mL, p = 0.004). Significative differences in PTH levels were observed according to the grade of hypertension in PA patients. Both hyperparathyroidism and CVD were found at higher rates in patients with PA. Patients with CVD exhibited significantly higher PAC values than patients without it (41.4 ± 18 vs. 21.4 ± 12 ng/dL, p < 0.001). Patients with hyperparathyroidism had higher rates of CVD than patients without it (58 vs. 24%, p = 0.018). Patients with PA and hyperparathyroidism manifested a higher rate of CVD than patients without this combination. A logistic regression showed an independent association of PAC and hyperparathyroidism with the presence of CVD in the total cohort. Conclusions: Hyperparathyroidism is associated with a higher probability of CVD both in PA and EH. The presence of hyperparathyroidism in PA seems to exacerbate the risk of CVD, with higher PTH levels associated with higher grades of hypertension in this cohort.