This study investigates the impact of photo-oxidised palm oil (PPO) and thermo-oxidised palm oil (TPO) diets on the kidneys of male wistar rats. A total of twenty (20) male Wistar rats were used in this study. The animals were divided into 4 groups (n=5) namely control (CT), fresh palm oil diet (FPO), thermo-oxidised palm oil diet (TPO) and photo-oxidised palm oil diet (PPO). The experiment lasted for 90 days. The animals were sacrificed under urethane anaesthesia and blood samples were collected via cardiac puncture for biochemical assay using the serum. The kidneys were harvested for histopathological studies. The results showed that there was a significant increase (p<0.05) in serum creatinine in TPO group when compared with the control, FPO and PPO groups. There was a significant increase (p<0.05) in blood urea nitrogen (BUN) levels in TPO group when compared with the control, FPO and PPO groups. There was also a significant increase (p<0.05) in BUN levels in PPO group when compared with the control group. Histopathological findings revealed the presence of mild and moderate lesion and atrophy of tubular epithelium as well as vacuolation of renal corpuscle, tubular necrosis in the PPO and TPO groups. The findings of this study revealed that extreme consumption of PPO and TPO is toxic to the kidney.