The effect of adding coriander fruits or its essential oil before and after irradiation at dose of 4 kGy to rat's diet was studied. The spice in different treatments had a significant hypolipidemic action. The levels of triglycerides were significantly decreased, while total cholesterol and glucose were non-significantly decreased in the serum of the animals of the experimental group which fed on diets containing coriander powder and coriander essential oil in all treatments comparing with the control group. The level of LDL and VLDL cholesterol was decreased while that of HDL cholesterol was increased in the experimental group compared to the control group. Also, liver and kidney functions were examined and there were no significant differences. The experiment showed there were no significant differences between treated groups and control group in blood hematology.