Background & Objective(s): Spirulina platensis is an incredibly powerful source of proteins, fibers and antioxidants. The aim of the study was to assess the nutritional value of Spirulina platensis cultivated in Egypt and study its effect on fasting blood glucose and lipid profile in diabetic rats. Methods: A total of one kilogram of Spirulina platensis was used in the study. The nutritional value of Spirulina platensis was characterized by measuring its proximate, vitamins, amino acids, minerals and antioxidants contents. We extended our analysis to study its effect on fasting blood glucose (FBG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), serum triglycerides (TG), and total cholesterol (TC) parameters in sixty male albino rats grouped as 10 control rats and 50 diabetic rats in five groups. The latter comprised 10 diabetic control rats and 40 test rats that were orally administered 10, 20, 30 mg/kg body weight Spirulina platensis and 300 mg/kg of the anti-diabetic medication Metformin respectively for four weeks. Results: Spirulina platensis contained high amount of high quality protein, as eight essential amino acids were present (56.79%). It was also a rich source of Ca, phenolic compounds and flavonoids (363.7, 997 and 711 mg/100g respectively). Spirulina significantly managed body weight of diabetic rats and reduced blood glucose level in treated groups compared to diabetic control by 67.8% and 68.3% in rats treated by 10 and 30 mg/kg body weight Spirulina respectively. Rats administered 30 mg/kg body weight Spirulina achieved decreased TG, TC, and LDL-C levels to reach 101.9, 75.43, and 6.2 mg/dl respectively, with improvement in HDL-C level by 58.7% compared to diabetic control rats. Conclusion: Chemical analysis of Spirulina platensis produced in Egypt showed high nutritional value with high concentration of several functional ingredients. In addition, its effect on the measured FBG, LDL-C, HDL-C, TG, and TC parameters in experimental rats was dose dependent.