In gastric cancer surgery, an extended radical operation is commonly performed; in cases of total gastrectomy, there is a tendency to perform splenectomy at the same time. Some surgeons have reservations regarding this treatment in connection with the possible preservation of the host immune resistance. Is it reasonable to accept, by simple analogy, with prophylactic lymphadenectomy the concept of the prophylactic splenectomy? To examine the value of prophylactic splenectomy in gastric cancer surgery, a comparable patient group was followed up, the non-splenectomized group showed a significantly better late survival rate than the splenectomized group (P < 0.05), the 4 yr survival rate being 63% in the former group and 36% in the latter group. Although these results do not necessarily contraindicate combined splenectomy, it seems desirable to reappraise the value of prophylactic splenectomy in cases having no metastasis in the splenic hilar and adjacent lymph nodes.