Germinated date palm seeds powder was employed, together with soybean flour, sugar, banana meal and maize meal for the preparation of a nutritional supplement. 12-day old male Wister rates were fed diets containing the supplement as a protein source, both with and without soybean flour; casein diets with 10 or 7% protein served as respective controls. Protein efficiency ratio (PER), net protein utilization (NPU), net protein retention (NPR) and digestibility were determined. Blood biochemical parameters (triglycerides, total cholesterol, LDL-cholesterol and HDL-Cholesterol were also measured in the animals and showed that all rats were in good health condition at the end of experiment. The obtained results for PER, NPU and NPR indicated that the supplement prepared with germinated date palm seeds powder was a good protein source, especially when soybean flour was added.