The present study was aimed to investigate the comparative antidiabetic potential of Nigella sativa seed extract and oil in an in vivo trial using rat animal model. The levels of antioxidants analysed in this study included catalase, vitamin C and bilirubin. NS methanolic extract and its oil were tested for their hypoglycemic effect against alloxanized diabetic rabbits (120mg/kg). The crude methanolic extract and the oil (2.5ml/kg/day) were given orally for 24 days that resulted in a significant reduction in glycaemia, particularly during the first 12 days of treatment (reductions of 58.09% and 73.27%, respectively), whereas the oil treated group normalised the levels of catalase (-69.23%), vitamin C (27.30%) and bilirubin (-51.48%) and the extract treated group normalised the levels of catalase (-65.38), vitamin C (24.15%) and bilirubin (-26.19%) at the end of the trial. The results have shown that the seed oil more significantly normalized the levels of serum catalase, serum ascorbic acid and total serum bilirubin as compared to the methanolic extract of Nigella sativa, so Nigella sativa seed oil (NSO) may be used as part of antidiabetic remedies against diabetes and utilized as a nutraceutical.