Complications of post-splenectomy, especially intra-abdominal hemorrhage can be fatal, with delayed or inadequate treatment having a high mortality rate. The objective of this study was to investigate the cause, prompt diagnosis, and outcome of the fatal complications after splenectomy with a focus on early diagnosis and management of hemorrhage after splenectomy. The medical files of patients who underwent splenectomy between January 1990 and March 2011 were reviewed retrospectively. The cause, characteristics, management, and outcome in patients with post-splenectomy hemorrhage were analyzed. Fourteen of 604 patients (1.19%) undergoing splenectomy had intraperitoneal hemorrhage: reoperation was performed in 13 patients, and 3 patients died after reoperation, giving the hospital a mortality rate of 21.43%; whereas, 590 of 604 patients (98%) had no hemorrhage following splenectomy, and the mortality rate (0.34%) in this group was significantly lower (P < 0.001). The complications following splenectomy, including pneumonia pancreatitis, gastric fistula, gastric flatulence, and thrombocytosis, in patients with postoperative hemorrhage were significantly higher than those without hemorrhage (P < 0.001). According to the reasons for splenectomy, 14 patients with post-splenectomy hemorrhage were grouped into two groups: splenic trauma (n = 9, group I) and portal hypertension (n = 5, group II). The median interval between splenectomy and diagnosis of hemorrhage was 15.5 hours (range, 7.25-19.5 hours). No differences were found between groups I and II in terms of incidence of postoperative hemorrhage, time of hemorrhage after splenectomy, volume of hemorrhage, and mortality of hemorrhage, except transfusion. Intra-abdominal hemorrhage after splenectomy is associated with higher hospital mortality rate and complications. Early massive intraperitoneal hemorrhage is often preceded by earlier sentinel bleeding; careful clinical inquiry and ultrasonography are the mainstays of early diagnosis.