A Multivariate analysis was done in all patients who developed post operative ARF, during the period 1990-1995 to determine the etiological spectrum and to identify various variables affecting the outcome. Of 140 patients (110 operated at SGPGI and 30 operated outside) 116 underwent elective surgery. The different types of surgery leading to ARF were urosurgery (3.5%), open heart surgery (32.9%), gastrosurgery (16.4%), pancreatic surgery (9.3%), obstetrical surgery (3.6%) and others (2.8%). The incidence of ARF in SGPGI patients was highest in pancreatic surgery group (8.2%) followed by open heart surgery (3%). The different etiological factors responsible for ARF were perioperative hypotension (67.1%), sepsis (63.6%) and exposure to nephrotoxic drugs (29.3%). Sixty-four patients (45.7%) required dialysis. The overall mortality was 45%. The mortality was highest in patients who underwent open heart surgery (89.1%) followed by pancreatic surgery (84.6%). The factors associated with high mortality, other than the type of surgery, were preoperative hypotension (p < 0.05), oliguria (p < 0.01), need for dialysis (p < 0.05) and multiorgan failure (p < 0.001). AM following emergency surgery had poor outcome, though not statistically significant. Perioperative sepsis (p < 0.05) and preoperative use of aminoglycoside (p < 0.05) were significantly higher in patients operated outside SGPGI. This was associated with higher incidence of ARF. Thus we conclude that presence of multiorgan failure, oligoanuria, preoperative hypotension and need far dialysis are poor prognostic markers in ARF following surgery.