Methamphetamine (METH) is a high stimulant for the nervous system, which is widely abused. Clinical reports indicated that METH has damaging effects on many organs. This study was done to assess the hepatotoxicity, nephrotoxicity and hematotoxicity of METH in rat model. Different doses of METH were used to assess its toxic effects on the liver, kidney and blood in rat model. To evaluate toxicity, serum biochemical markers such as ALT, AST, ALP, Cr, BUN, antioxidant parameters, histopathological examination as well as blood parameters were measured. Administration of METH significantly increased the liver enzymes and induced oxidative damage in the liver, which confirmed by histopathology. Also, in the kidney, minor increases in BUN and Cr and slight oxidative damage were observed. In the blood, METH-induced reduced WBC level and slightly increased RBC and platelet concentrations and RBC indexes. Also, the total antioxidant capacity of the blood dropped. Our finding showed severe liver damage and relatively less kidney damage as well as changes in blood parameters due to methamphetamine administration. Also, this study confirmed that oxidative stress plays key roles in the METH-induced damage.