Coffee has been linked to all kinds of health problems- from diabetes to increasing blood pressure to weight gain and increased risk for a heart attack. Allium cepa (onion) is a special delicacy that contains physio-pharmacological active ingredients that for centuries has been exploited as folk remedies for the treatment of diseases. In this study, the protective effect of Allium cepa on impairment of blood glucose formed by coffee was investigated. Five groups of 10 healthy male wistar rats were used for the study. Hydromethanolic extract of Allium cepa (AC)100mg kg-1; coffee (C) 500mg kg-1; vitamin E (VE) 400mg kg-1; and combinations of Allium cepa and coffee(ACC); and vitamin E and coffee(VEC) respectively were administered orally to each group of rats daily. While blood glucose levels were estimated at age 0, 21 and 42 days with electronic glucometer, the corresponding intrinsic oxidative stress markers- superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione (GSH) and malondialdehyde (MDA) were analyzed after age 42 days using standard methods. GSH ,GPx , SOD , CAT and MDA activities between control, coffee, Allium cepa, combinations of Allium cepa and coffee; and vitamin E and coffee groups were found to be statistically significant(<0.05). Compared to normal control and coffee groups, ACC>AC>VE>VEC produced a significant time-dependent glucose lowering efficacy with up regulations of GSH, GPx CAT and SOD and diminution in MDA. Allium cepa as one of the most important nutrient sources worldwide were observed to ameliorate some increases in blood glucose oxidative damage induced with coffee. Additionally, combination of Allium cepa and coffee improve glycaemic control, and provided additional metabolic benefits, not achieved with either coffee or Allium cepa alone.