Background and Objective: Due to the presence of some evidence for anti-diabetic and antioxidant activity of Tribulus terrestris (TT), this study was designed to investigate the anti-nociceptive effect of TT in streptozotocin-diabetic rats using formalin test and hot tail immersion tests. Materials and Methods: Rats were divided into control, TT-treated control, diabetic, sodium salicylate (SS)-treated diabetic (as positive control), and TT-treated diabetic groups. The treatment groups received oral administration of TT-mixed pelleted food (3%) for 5 weeks. Serum level of malondialdehyde (MDA) as a reliable marker of lipid peroxidation was also measured. Results: TT treatment of diabetic rats reduced pain score only in chronic phase of the formalin test (pConclusion: Taken together, 5-week administration of TT could attenuate nociceptive score in chronic phase of formalin test in streptozotocin-induced experimental model of diabetes mellitus and has no significant effect on thermal pain threshold and part of its beneficial effect is exerted via attenuation of lipid peroxidation and possibly reduction of oxidative stress.