Plants with antidiabetic effects are being used in traditional medicine for thousands of years and phytogenic products continue to play an essential part in pharmacy and medicine. The need to investigate highly effective and safe drugs for diabetes mellitus remains a significant challenge for modern medicine. Myrtus communis L. fruits and leaves had medicinal and nutritive properties and were utilized in the traditional medicine as an antidiabetic agent. This study was designed to investigate the hypoglycemic, and hypolipidemic effects of M. communis fruits hydroalcoholic extract also pointed toward the assessment of its role in oxidative-antioxidative systems in Streptozotocin-induced (STZ) diabetic rats. Forty male Wistar rats were randomly divided into four groups which were supplemented with M. communis fruits hydroalcoholic extract in drinking water for five weeks. The Malondialdehyde levels (MDA) in kidney, heart, liver and muscles tissues were estimated by using High-Performance Liquid Chromatography (HPLC). In addition, the blood glucose levels and serum insulin levels were assessed by the radioimmunoassay. While, the Total Cholesterol (TC), High-Density Lipoprotein- Cholesterol (HDL-C), Triglyceride (TG), Erythrocyte Superoxide Dismutase (SOD) and whole blood glutathione peroxidase (GSH-Px) were estimated utilizing commercial biochemical kits. The experimental groups of rats which were treated with M. communis fruits hydroalcoholic extract showed a reduction in serum glucose, lipid profile, and tissues malondialdehyde levels and an increase in insulin, serum paraoxonase, arylesterase, erythrocyte SOD, and the whole blood GSH-Px activities. These findings suggest that M. communis fruit hydroalcoholic extract has hypoglycemic, hypolipidemic and oxidative stress inhibitory activities in STZ-induced diabetic rats. Future studies are needed to address the role of M. communis fruits extract on humans that have diabetes.