Aim -Our aim in this study is evaluating the red blood cell distrubition width (RDW) and glycated hemoglobin (HbA1C) relation in nondiabetic and diabetic people who applied to our hospital and showing the usability in disease follow-up. Material and Methods -Main data of this research is the data of patients (diabetic and nondiabetic) who applied to internal diseases polyclinic between July 1, 2013 and November 31, 2014 and whose RDW, HbA1C, white blood cell, hemoglobin, and hematocrit were controlled. 82 diabetic and 32 nondiabetic patients were included in this study. Results -No statistically significant difference was observed between the diabetic and nondiabetic groups in age, male and female distribution and RDW. No statistically significant correlation was observed between RDW and age and HbA1C in order in the nondiabetic group. While a correlation which is statistically significant and in the same direction was determine between age and RDW among the diabetic group, a statistically significant correlation was not between HbA1C and RDW. Among all cases a correlation which is statistically meaningful and in the same direction was detected between age and RDW. But a statistically significant correlation was not found between HbA1C and RDW among all cases. Conclusion -According to the available results, no statistically significant correlation was determined between HbA1C and RDW in the nondiabetic patients, diabetic group or in total. But in order to provide more clearance, we believe that studies with more patients would be useful.