Levamisole is a broad-spectrum nicotinic anthelmintic drug; widely used in veterinary medicine. Levamisole actions are variable depending on storage temperature and administration route. The present study was conducted to test levamisole effects on immune responses and antioxidant status of rats at different storage temperature and administration routs. The experimental rats were allocated into four experimental groups and two controls. Group 1 was given levamisole orally. Group 2 was injected levamisole intramuscularly. In group 1 and 2 levamisole was stored at 4 degrees C for 72 h and given every two days for three weeks at a dose of 2.5 mg kg(-1) body weight. Group 3 and 4 were treated same as group 1 and 2 but levamisole was stored at 37 degrees C. Serum levels of total IgG and IgA and plasma levels of glutathione reductase (GSSG-R), TAC concentrations in addition to GST and GSH-Px activities were measured. The results indicated that the storage of levamisole at 4 degrees C significantly increased serum IgG and IgA levels in rats and improved rat's antioxidant status through significant increase in glutathione related enzymes (GSSG-R, GST and GSH-Px) and the TAC. Levamisole stored at 37 degrees C increased measured antioxidant biomarkers but decreased the rats' non-specific humoral immunity. Moreover, the intramuscular administration induced better antioxidant properties than oral administration of levamisole. In conclusion, levamisole actions could be specifically directed towards certain types of immune responses due to changes in storage temperature with better response to injectable routes than oral routs with more antioxidant activities.