The aim of the present study was to evaluate the effect of Agaricus sylvaticus on the blood sugar, cholesterol, HDL, triglycerides, glutamic-pyruvic transaminase (GPT), alkaline phosphatase, iron, transferrin, and urea level in the plasma of rats with type 1 diabetes mellitus (DM1) induced by streptozotocin. Here, GPT is linked to diabetes mellitus.