Spleen is a wedge-shaped highly vascular organ which is mainly located in the left hypochondrium and partly in the epigastrium. It is sandwiched between the fundus of the stomach and diaphragm. It obliquely lies along the axis of the 10th rib. It is marked downwards, forwards, and laterally making an approximate angle of 45 degrees with the horizontal plane. The function of spleen is to filter the blood. When blood enters spleen the healthy cells pass through the filter whereas the unhealthy cells don’t. The latter undergo phagocytosis by macrophages. Spleen extracts iron from unhealthy and malformed cells to recycle it in the making of new red blood cells. Moreover, spleen couples with lymph nodes and fights against intruders. This indicates its role as assistant to immune system of body.