Objectives: The serum Insulin-like growth factor-binding protein 7 (IGFBP7) levels were tested to predict acute renal damage that may develop in patients with stage III–IV heart failure who were treated with intravenous diuretics in the emergency department. Method: Patients with stage III–IV heart failure (n=84) were included in this prospective observational study. All patients were treated with IV diuretic therapy in accordance with a predetermined protocol. The serum IGFBP7 and creatinine levels were analyzed at the beginning of the treatment (0 h), 6th, and 12th hours. The creatinine level and glomerular filtration rate (GFR) at baseline were compared with the 12th hour values. The results were classified according to the RIFLE (Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease) criteria for each patient. The patients were divided into two groups as those in any RIFLE group (RIFLE (+)) and those without (RIFLE (−)). The groups were compared in terms of IGFBP7 levels. Results and Discussion: 0, 6th, and 12th hour levels of IGFBP7were significantly different between the RIFLE + and RIFLE – groups. (p=0.036, 0.042, and 0.006, respectively). The IGFBP7 levelswere higher in RIFLE (+) group.However, the IGFBP7 values did not increase with time. In the ROC curve analyze for IGFBP7 levels, the cutoff with the highest sum of sensitivity (0.80) and specificity (0.69) was 118.71. Conclusions: The serum IGFBP7 levels can predict the risk of developing AKI before the diuretic treatment in the patients with stage III–IV heart failure.