Abstract Objective: Background: Although some guidelines suggest the screening for endocrine hypertension (eHy) in subjects at risk, the eHy actual prevalence and its causes in adult hypertensives at risk of endocrine disorders are still unknown. The aim of the present study is to evaluate the eHy prevalence in a group of adults at risk for endocrine disorders. Patients and Methods: We consecutively screened patients with hypertension (n = 120), referred to our outpatient clinic for suspected endocrine hypertension due to the presence of: malignant Hy, grade 3 or resistant Hy, sudden new onset of Hy or its unexpected worsening, Hy onset before 30 years without family history or cardiovascular risk factors and Hy with disproportionate organ damage. We excluded all subjects with known secondary hypertension and/or taking drugs interfering with cortisol secretion. Eventually, 47 patients (35 F, mean age 53.5 ± 14.7) fulfilling the inclusion and exclusion criteria have been enrolled. In all patients we performed: cortisol and aldosterone secretion levels, thyroid function, insulin-like growth factor 1, calcium-phosphate metabolism, urinary fractionated metanephrines and 24 h ambulatory blood pressure (BP) monitoring. Design and method: We found 24 patients with eHy (9, 8, 3, 1, 1, 1, 1 with primary hyperaldosteronism, subclinical hypercortisolism, pheochromocytoma, acromegaly, hyperthyroidism, hyperparathyroidism and still uncertain cause, respectively). eHy patients had higher BP levels (mean BP 110.7 ± 15.3 vs 100.8 ± 7.3 mmHg, p < 0.005) and a more frequently altered dipping pattern (non dipping or rising patterns) (60% vs 9.1%), as compared to those with essential Hy, while age, body mass index (BMI), familiar history of hypertension, gender, prevalence of diabetes and of obesity were comparable between the two groups. The altered dipping pattern was found to be independently and directly associated with eHy (odd ratio, OR, 28.9, 95% confidence interval, 95%CI, 1.26–667.2, p = 0.035), and age (OR 1.15, 95%CI1.01–1.3, p = 0.031, but not with BMI, family history of Hy and mean BP levels. Results: Among patients at risk for eHy, about 50% of individuals are in fact affected by an endocrine disease potentially causing Hy. In Hy patients, the presence of an altered dipping pattern may be considered highly suggestive for the presence of an otherwise asymptomatic endocrine disorder.