Introduction: Low molecular weight heparin (LMWH) is used as anticoagulant in diseases characterized by possible thrombosis, as well as for thromboprophylaxis in surgery. The administration of LMWH preoperatively and postoperatively allows satisfactory thromboprophylaxis of patients undergoing surgery. Their application can reduce the number of platelets. Aim: To determine what effect Reviparin has on platelet values postoperatively in patients undergoing open cholecystectomy. Methods: The study was conducted at the Clinic for Anesthesia and Resuscitation of the Clinical Center of the University of Sarajevo. A retrospective study was performed that included data analysis for 33 patients undergoing open cholecystectomy over a two-year period. There were 22 male and 11 female patients out of a total of 33 patients. Platelet values from laboratory findings of patient's medical history were monitored for 5 days. The values found were recorded in a table containing the patient's first and last name, gender, age and platelet value. All patients had the same endotracheal anesthesia with Propofol, Fentanyl, and Atracurium supplemented with oxygen and nitric oxide at the appropriate dose. All of the patients received same dose of 0.25ml (1432 IU) Reviparin (Clivarin) from Abbott GmbH & Co.KG, preoperatively and postoperatively. Patients undergoing laparoscopic surgery as well as patients receiving other low-molecular-weight heparin or receiving higher doses of Reviparin were excluded from the study. Statistical analysis was performed using the MedCalc v12.7 statistical package for biomedical research. Results: An analysis of gender representation in the total sample shows that there was 22 or 66.7% of males while there was 11 or 33.3% of female patients. Analysis of platelet values indicates that there is no statistically significant correlation with gender, but that there is a statistically significant correlation between platelet values between samples, ie. that patients who had higher preoperative values retained more platelet values even during postoperative measurements. Conclusion: Platelet values do not change significantly postoperatively with the use of prophylactic doses of Reviparin, after an open cholecystectomy.