Introduction: “The kidneys perform a critical regulatory function within the cardiovascular system.” Burn injury of the skin increase local vascular permeability and and exudates rich in protein and salt leaks from the plasma to produce burn oedema. Prevention, identification and treatment of actual renal failure that occurs when the insult exceeds the capacity of normal protective renal homeostatic response to shock, have to be considered on this background. Material and Methods: 62 cases of both sex and different age group coming to surgical emergency within 48 hours after sustaining burn injury and involoving more than 10 percent body surface in children and more than 15 percent in adults. Results: Investigations was done to evaluate renal function by following tests- PSP excretion on 1st, 3rd and 7 th post op day, level of blood urea, serum creatinine level, serum sodium level, serum potassium level.