Introduction: This study was established to assess the effects of low dose enoxaparin on plasma malondialdehyde levels during laparoscopic cholecystectomy as a model of ischemiareperfusion. Materials and Methods: Fifty patients, scheduled for laparoscopic cholecystectomy, were randomized into two groups of 25 patients in each. In enoxaparin group, patients had 20 mg/0.2 ml subcutaneous (sc) enoxaparin 2 hr before surgery. Blood samples were obtained for malondialdehyde, alanine transferase, aspartate transferase, measurements before the insufflation, 1 min before deflation, and 20 min after deflation. Results: Plasma malondialdehyde concentrations were insignificant between enoxaparin and control groups before insufflation (1.64 ± 2.66 vs. 2.45 ± 4.42 μmol l -1; p = 0.44) and 1 min before deflation (1.55 ± 2.61 vs. 3.66 ± 5.68 μmol l -1; p = 0.38). Malondialdehyde levels significantly increased in control group 20 min after deflation in respect to enoxaparin group (1.52 ± 2.67 vs. 6.04 ± 7.85 μmol l -1), (p = 0.049). In control group, plasma malondialdehyde concentrations increased significantly compared with initial level throughout the study (p = 0.001). Within enoxaparin group, no statistically significant change was observed (p = 0.28). Plasma alanine transferase and aspartate transferase levels increased similarly in both groups during the study (p > 0.05). Alanine transferase and aspartate transferase increases within each group were statistically significant for all times (p < 0.05). Discussion and Conclusions: As a conclusion, mini dose of enoxaparin used sc'ly 2 hr before the operation, prevented the malondialdehyde increase during reperfusion period after laparoscopic cholecystectomy without causing any bleeding disorder while having no effect on serum alanine transferase, aspartate transferase increase. © 2011 Informa Healthcare USA, Inc.