In this study was investigated effects of borax (BX) on inflammation markers, haematolojical parameters and total oxidant (TOS)-antioxidant status (TAS) in rats applied 3-methylcholanthrene (3-MC). In this research a total of 24 Wistar Albino rats were used. They were divided into 4 groups each containing 6 rats. 1st group was separated as a control group. 3-MC was applied twice a week first 2 weeks 25 mg/kg dose to the 2nd group with i.p. way. BX was given to 3rd group 300mg/L/day dose with drinking water during 150 days. 3-MC was applied twice a week first 2 weeks 25 mg/kg dose with i.p. way and BX were given with drinking water during 150 days to 4th group. At the end of the study blood analysis, tumor necrosis factor alpha (TNF-alpha) and interleukin 1 beta (IL-1 beta) levels in 3-MC group; TOS and oxidative stress index (OSI), platelet (PLT) levels in 3-MC and 3-MC+BX groups showed significantly increases when compared to other groups. It was determined that lymphocytes % (LY%) of ever 3 groups were significantly higher; however, neutrophil % (NEU%) were significantly fewer according to control group. Haemoglobin (HGB) and hematocrit (HCT) values of 3-MC+BX groups showed significantly decrease according to other groups (P <= 0.05). Mean corpusculer volume (MCV) in 3-MC and 3-MC+BX groups showed significantly decrease when compared to other groups (P <= 0.05). As a result, in case of exposure to 3-MC, long-term use of BX with oral ways may not decrease oxidative stress, may changes haematolojical parameters such as, WBC, LY%, NEU%, PLT, HGB, HCT, MCV. However, these changes remain within physiological limits. Even so, in the use of BX should be considered use of iron. Furthermore, BX with the abovementioned dosage may be used to reduce the levels of TNF-alpha, IL-1 beta, IL-6 being inflammation and cancer markers.