Objectives: Cardiac surgery with cardiopulmonary bypass provokes systemic inflammatory response, which may cause organ dysfunction. Studies have suggested that pre-operative statin therapy can reduce morbidity and mortality associated with cardiac surgery; the mechanism for this remains unclear. We hypothesise that underlying mechanism of action for these effects of statins is through inhibition of neutrophil transendothelial migration. Methods: We recruited 151 patients undergoing cardiac surgery. Of these 41 patients were on no-statin; 48 patients on low-dose (10 30 mg) and 62 patients were on high-dose statin (40 80 mg). Ex vivo neutrophil migration was performed on pre-operative blood samples of 90 patients. Of these 90 patients we used 36 patients to assess the levels of TNF-α and sICAM-1. Clinical parameters of total 151 patients were assessed to analyse outcome. Results: Ex vivo neutrophil migration was decreased in high-dose statin group when compared to neutrophils isolated from no-statin or low-dose statin groups (p < 0.001). Serum TNF-α levels were lower in the high-dose statin group (p = 0.002) and sICAM-1 levels were decreased in both low (p = 0.02) and high-dose statin (p = 0.01) groups. Conclusion: Our study demonstrates that high-dose statins reduce ex-vivo transendothelial neutrophil migration, TNF-α and sICAM-1 serum levels suggesting that statins may help in decreasing the post-cardiac surgery morbidity.