The extensive performance of splenectomy worldwide for patients suffered from splenic trauma has given rise to high risks of postoperative complications, which has been attracting increasing attention in recent years. Nowadays the spleen is regarded as a versatile organ of the human body, invested with various excellent properties. The spleen has been recognized to take a great part in lipid metabolism. While removal of the spleen intends to alter lipid values, especially with an elevated LDL, splenic autotransplantation is able to normalize these lipid alterations. What is more, conservative surgical procedures like subtotal or partial splenectomy, could as well, afford a correction of dyslipidemia. At the same time, clinically, splenectomy demonstrates a high rate of atherosclerosis (AS), whereas non-surgical treatment after splenic trauma shows unchanged propagation of AS. Based on the intimate relationship between serum lipids and AS, the lipid changes modulated by splenectomy are believed to be responsible for the development of AS. Therefore, a “splenic factor” is most likely present in the regulation of lipidation and AS. Several theories have been postulated to elucidate the possible mechanism involved, among which most are primarily based on its forceful natural immune function, that is to say, the mononuclear phagocytic system.However, the accurate mechanisms behind this mysterious phenomenon still remain unclear so far. Of importance, lipid fractions should be monitored consecutively in case of inevitable splenectomy.