The effects of T. Polium leaves extract were evaluated on rats during three weeks of administration. Blood picture and some biochemical parameters were investigated. Significant decrease was demonstrated in red blood corpuscles (RBCs), hemoglobin (Hb), and packed cell volume (PCV). However, other blood indices, mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) and mean corpuscular volume (MCV) were not changed. There was significant decrease in the platelets (PLT), while white blood cells showed a significant increase. Serum glucose level change was insignificant while the level of serum cholesterol was significantly reduced. Significant increases were found in the serum activities of glutamate oxaloacetate transaminase (GOT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) while glutamate pyruvate transaminase (GPT) was decreased.