An evaluation of the effects of daily oral administration of sodium nitrate for 30 days on serum non-protein nitrogen constituents, eg, urea, uric acid and creatinine, glucose, cholesterol and triglycerides was carried out. The daily oral administration of NaNO3 for 30 days at levels of 25, 75,150 and 300 mg/kg bw increased significantly the concentration of uric acid by 43.68, 68.97, 51.72 and 75.86%, respectively compared to the control level. Nitrate administration raised up the concentration of urea in rabbit's blood serum, in general, at the twentieth and thirtieth days of inoculation. Administration of 150 and 300 mg NaNO3/kg bw for 30 days caused a significant increase in the creatinine level when compared with the control level. In general, glucose content of rabbit's blood serum, increased significantly in response to the administration of NaNO3 levels at the different tested intervals within the thirty days of inoculation. Serum triglycerides content, of the rabbits treated with NaNO3 at the different levels, decreased significantly at the twentieth and thirtieth days of inoculation. Nitrate administrations for 30 days, at the different tested levels, have little effect on the cholesterol concentration. In the twentieth and thirtieth day of inoculation, cholesterol concentration slightly decreased in the serum of treated rabbits in response to the different levels of NaNO3. Finally, nitrate administration for 30 days, even at the lowest tested level, ie, 25 mg/kg bw, had harmful effects on liver, kidney, carbohydrate and lipid metabolisms