Background: Methods of reducing blood loss in surgical procedures such as spinal disc herniation, which are characterized by severe bleeding, can reduce the need for blood transfusion and thereby the risk of infectious diseases transmission, transfusion reactions, acute lung injury, graft-versus-host disease (GVHD), hypothermia, coagulation disorders and metabolic complications. Anti-fibrinolytic drugs (e.g. Aprotinin, aminocaproic acid, desmopressin and tranexamic acid) and controlled hypotension (monitored reduction by medication) are among these methods.Objectives: In our clinical trial, two methods of aprotinin and controlled hypotension are compared in terms of their efficacy in reducing blood loss.Patients and Methods: 70 patients undergoing spinal disc herniation were randomly divided into two groups of controlled hypotension (treated with nitroglycerin: starting with 5 μg/minute to reach an MAP of 55 - 60 mmHg, with an increase of 5 μg/minute of the drug in every 3 - 5 minutes) and aprotinin (0.5 million units injection before surgery). The anesthesia was administered similarly to both groups and blood pressure and heart rate were recorded every 5 to 15 minutes. Moreover, the amount of bleeding and the surgeon satisfaction were measured.Results: 70 patients were identical in terms of demographics and the length of surgery. The two groups were not statistically different in terms of mean change in systolic, diastolic and mean blood pressure and heart rate at different times. The severity of blood loss measured on Boezarrt scale for low, medium and severe bleeding was respectively 21 (30%), 27 (39%), and 12 (31%). The extent of surgeon satisfaction with the operation room measured on a 3-point Likert scale (poor, medium and good) was 18 (26%), 40 (57%), and 12 (17%), respectively. The results were almost corresponding in both groups. Also, the two groups were identical in terms of calculated blood loss and the need for additional intraoperative medication.Conclusions: In intervertebral herniated disc surgery, aprotinin and controlled hypotension treatments yielded similar results in terms of reducing blood loss and surgeon satisfaction with the field of operation.