Both non-dipping hypertension and high red blood distribution width (RDW) values are associated with adverse cardiovascular events and inflammatory status in cardiovascular disease and the general population. Thus, in this study we investigated relationship between RDW and non-dipping hypertension compared with normotensives. A total of 907 participants were included in the study. The nocturnal decline in blood pressure is by less then 10% of the daytime value has been termed non-dippers. According to the values of ambulatory BP, the patients were divided into three groups as non-dipper hypertensive (n=246), dipper hypertensive (n=250), and normotensive (n=411) ones. There were no significant differences among groups regarding baseline demographic properties and biochemical characteristics. Non-dipper and dipper hypertensive groups had higher leukocyte and neutrophil counts than normotensive group (p<0.001) but the leukocyte and neutrophil counts did not differ between the hypertensive groups. There was no difference in RDW levels among non-dipper, dipper and normotensives (13.3(22.8-11.2), 13.1(22.8-11.2), 13.1(19.2-11), p=0.53, respectively). RDW level was not associated with dipper and non-dipper hypertension. There was a positive correlation between the RDW level and neutrophil counts and systolic blood pressure but the correlation was weak.