Introduction: Primary Aldosteronism (PA) is a secondary form of hypertension characterized by an autonomous and inappropriately high production of aldosterone. Its prevalence is 5-12% and the two main subtypes are the Bilateral Adrenal Hyperplasia (BAH) and the Aldosterone-Producing Adenoma (APA). In this study, we report the results of an evalutation of some patients diagnosed with PA in a Nephrology Unit between 1987-2011. Patients and methods: As much as 54 patients were screened for PA by measuring Plasma Aldosterone Concentration (PAC) and Plasma Renin Activity (PRA), and by calculating the aldosterone/renin ratio (ARR). Confirmation tests were performed on 47 patients with PAC ≥ 15 ng/dL and ARR ≥ 40. Subtype diagnosing was possible through adrenal CT scan, scintigraphy and adrenal venous sampling. Results: As much as 31 patients were diagnosed with PA. In 17 of them, the concordance of CT, scintigraphy and AVS findings made it possible to determine the subtype diagnosis: BAH in 10 and APA in 7 patients. Conclusions: Our results confirm the increasing frequency of diagnosis of PA among patients investigated for resistant hypertension. Early detection of PA in nephrological settings is important because of the relationship between aldosterone and kidney function.