Introduction. It is known that in children with chronic kidney disease (CKD), cardiovascular damage starts in the form of arterial stiffness. There are risk factors other than the traditional ones such as arterial stiffness hypertension, obesity, hypercholesterolemia, and insulin resistance. Vitamin D deficiency is rather common in CKD, and it was introduced as a risk factor for atherosclerosis; however, its relationship with arterial stiffness is not known completely. The purpose of this study was to research the relationship between 25-hydroxyvitamin D levels and arterial stiffness.