Overwhelming infection after splenectomy remains a problem despite the introduction of vaccine and antimicrobial prophylaxis. To evaluate prospectively various procedures proposed for salvage of the spleen, we measured reticuloendothelial function for two to five years in 51 patients who had initially presented with abdominal trauma and suspected splenic rupture. The mean percentage of pocked erythrocytes and the clearance of antibody-coated autologous erythrocytes in 8 patients who had splenic repair and in 6 who had partial splenectomy were the same as in 11 controls with intraabdominal injury that did not involve the spleen. The mean percentage of pocked erythrocytes remained significantly elevated in 19 patients who had undergone total splenectomy without autotransplantation of splenic tissue. One of seven patients who underwent splenic autotransplantation had a normal level of pocked erythrocytes 18 months after surgery, and a second patient had only a slight elevation at 24 months. The mean (+/- SEM) half-time clearance of labeled erythrocytes was significantly longer in the group that had total splenectomy without autotransplantation (421.1 +/- 74.5 hours) than in the autotransplantation group (91.6 +/- 20.0) or in the controls (5.4 +/- 2.0). We conclude that reticuloendothelial function was better preserved after partial splenectomy and splenic repair than after splenic autotransplantation, but that autotransplantation was superior to total splenectomy and appeared to be safe. Splenic autotransplantation deserves further study in patients who have had splenic trauma when other surgical maneuvers to save the spleen are not possible.