This research was carried out to study the effect of whole wheat and millet flours on the nutritional status on experimental rats. Adult 24 white male albino rats (Wister) weighed 181-205 gm and aged 7-8 weeks were obtained from animal house in Medical Research Center in University of King Abdel-Aziz, Jeddah. The rats were divided into (4) groups; First group was considered the control. They were fed on basal diet containing starch. The remaining experimental rats were divided into (3) groups: one group was fed on the basal diet but the starch was displaced by wheat flour, second group the starch was displaced by wheat flour (50%) and millet flour (50%). The third group the starch was displaced by millet flour. The period of experiment was four weeks. Food intake was determined daily, body weights were determined weekly. At the end of experiment food efficiency ratio (FER) was calculated.                                               The rats were anesthetized with ether and blood samples were taken by eye vein. The rats were sacrificed and the organs including liver, heart, kidneys, lungs and spleen separated and weighted. Some biochemical parameters were determined in blood and serum including hemoglobin, proteins, glucose and lipids. The result showed that: the whole wheat flour group gave the highest in weight gain and FER. Millet flour group had the highest in haemoglobin, total protein and albumin among the experimental groups. In addition the millet flour intake caused increase in HDL-cholesterol level but were decreased serum, glucose, TC, TG, LDL-cholesterol and VLDL levels. The results showed that using millet flour improved the nutritional and health status of rats compared to wheat flour. According to that it is recommended to use millet flour in human foods to avoid the chronic diseases like anemia, diabetes mellitus and dyslipidemia