Abstract: Background and Objective: The management of diabetic hyperglycemia, dyslipidemia and oxidative stress status are the key elements in the protection of diabetic complications. The present study was hypothesized to evaluate the antidiabetic, antihyperlipidemic and antioxidant effects of thymoquinone on streptozotocin-induced diabetic albino rats. Materials and Methods: The rats were divided into 2 categories; pre-treated and treated groups. Thymoquinone (50 mg kg–1 b.wt.) was intraperitoneally injected day after day for 2 weeks pre and 2 weeks after induction of diabetes for the pre-treated group and 2 weeks after induction of diabetes for treated group. Results: The current study revealed that thymoquinone administration caused amelioration in hyperglycemia, hypoinsulinemia, dyslipidemia, impaired antioxidant defense system and upregulation to PPAR-γ and GLUT4 genes expression as compared to the diabetic rats. Conclusion: The current results revealed the hypoglycemic, hypolipidemic and protective effects of thymoquinone against diabetes via potentiating insulin secretion and action, modulate PPAR-γ and GLUT4 genes expression and also by its potent antioxidant effect.