Dendritic cells (DCs) play an important role in T cell alterations in primary hypertension (PH). We determined the numbers and maturation markers of peripheral blood total DCs (tDCs), myeloid cells (mDCs), and plasmacytoid cells (pDCs) and their association with hypertension-mediated organ damage (HMOD) markers and selected immune parameters in 30 adolescents with white coat hypertension (WCH), 25 adolescents with PH and a group of 35 age- and sex-matched children with normotension. Using multicolor flow cytometry, expression of maturation markers (CD86 and CD83) in tDCs (Lin1-/HLA-DR+), myeloid DCs (Lin1-/HLA-DR+/CD11c+) (mDCs), and plasmacytoid DCs (Lin1-/HLA-DR+/CD123+) (pDCs) and the distribution of peripheral Th17-bearing and T-reg cells were defined. In subjects with hypertension, carotid intima-media thickness (cIMT), left ventricular mass index (LVMI), and pulse wave velocity (PWV) were assessed. Compared with WCH and subjects with normotension, subjects with hypertension had reduced tDC and pDC numbers, an increased percentage of mDC subsets, an elevated mDC/pDC ratio, an increased population of mature mDC and pDC subsets bearing CD83 of high density, a decreased subset of CD86-bearing pDCs, and increased expression of DC activation markers (HLA-DR, CD86), as well as CD11c (mDCs) and CD123 (pDCs). PWV, LVMI, and cIMT values correlated negatively with tDCs and pDCs and positively with mDC numbers. Expression of DC maturation/activation markers (CD83, CD86, HLA-DR, CD11c, and CD123) correlated positively with PWV. Certain DC characteristics of WCH subjects resembled those of PH subjects (decreased tDC frequency and upregulation of activation marker expression). These changes correlated with HMOD. WCH subjects presented a DC phenotype that was intermediate between the normotensive and hypertensive phenotypes.Keywords: arterial stiffness; children; dendritic cells; lymphocyte maturation; primary hypertension.