The spleen is a secondary lymphoid organ that belongs to the reticular-endothelial system, directly connected to blood circulation. The spleen is greatly involved in the immune response, especially against capsulated bacteria. Splenectomy plays a fundamental role in the treatment of numerous pediatric hematologic disorders. Taking into account all the possible complications (especially infections) linked to this procedure, alternatives to total splenectomy have been sought. Partial splenectomy has been proposed as a treatment that allows the reduction of infectious risk. This approach has proven safe and feasible in most patients, but multicentric and prospective studies are necessary to more accurately define the indications for performing partial splenectomy. However, vaccinations and antibiotic prophylaxis remain fundamental for preventing serious infections, even in the case of partial splenectomy. We review anatomical and functional properties of the spleen, with a focus on medical or surgical indications to splenectomy, aiming to give practical educational information to patients and their families after splenectomy. Furthermore, we discuss the feasibility of partial splenectomy in children with hematologic diseases who require splenectomy.