This study was carried out to find out the extent of oxidation and its effects of oxidation if any on the renal handling of Na+, Cl-, K+ and HCO3- in rats fed open market purchased palm oil. Forty male wistar rats (weighing 140-160grams) were randomly distributed into three groups of ten rats each viz: control, fed normal rat chow, FPOmill (fed 15% mill fresh palm oil diets), FPOmarket (fed 15% w/w open market purhased fresh palm oil diets) and PPO (fed 15%w/w photoxidized palm oil diets) groups. Animals received water ad libitum. The experiment lasted for 12 weeks. Blood and Urine samples were collected at the end and the concentations of Na+, Cl-, K+ and HCO3- were determined. Mean plasma concentrations of Na+, Cl+, and HCO3- of FPOmarket and PPO groups were significantly (P<0.001, P<0.001 and P<0.05 respectively) lower than control and FPOmill groups. Plasma potassium levels showed the reverse. The urine concentration of Na+ and Cl- of the FPOmarket and PPO groups were significantly (P<0.001) higher than the control and FPOmill groups; The urine concentrations of K+ in the control and FPOmill groups were significantly (P<0.0) higher than the FPOmarket and PPO groups. The urine bicarbonate levels of the FPOmarket were significantly (P<0.05) lower than that of FPOmill. The urine output of the FPOmarket and PPO groups were significantly (P<0.001) lower than control and FPOmill groups. In conclusion, open market “fresh” palm oil has undergone some oxidation and is detremental to health. Its consumption should therefore be discouraged.