Splenic injuries, like other blunt traumatic injuries, are increasingly treated with non-operative management. Angiographic embolization (AE) has emerged as an alternative modality for treatment of splenic injuries. We hypothesized that splenic embolization would lead to equivalent, if not improved, outcomes in terms of mortality, total costs, complications, and duration of stay. A retrospective review of a prospective data set was performed for all adult splenic injuries admitted to our level I trauma center from 2000 through 2003. Demographics, number of red cell units, emergency department hemodynamics, costs, and outcomes were examined. The operative group included those who underwent computed tomography (CT) first then went to the operating room (OR) (CT+OR) or those who went directly to the OR. There were 25 CT+OR and 24 AE patients of 164 blunt splenic injuries. After univariate analysis, higher injury severity score (ISS), lower systolic blood pressure, lower pH, and higher packed red blood cell transfusions were associated with increased mortality and duration of stay. The splenic Abbreviated Injury Scale (AIS; mean +/- SD) was the same for AE compared to CT+OR patients (3.8 +/- 0.4 vs 3.5 +/- 0.9). Although the AE group was older (50 +/- 20 vs 36 +/- 13 years, P < .01), Glasgow Comma Score (13 +/- 4 vs 11 +/- 5), age, highest heart rate (109 +/- 24 vs 120 +/- 43), and splenic AIS were not predictive of the need for an operation. Abdominal complications were lower in the AE group compared to the CT+OR (13% vs 29%), but mortality was not different (8% vs 4%). Total costs were similar for both groups after adjustment for ISS, GCS, pH, pretreatment transfusions, and spleen AIS (AE, $49,300 +/- $40,460 vs CT+OR, $54,590 +/- $34,760). The non-operative failure rate in this study was 2%. AE of splenic injuries is safe and associated with fewer complications. The spleen AIS, heart rate, age, and GCS did not correlate with the need for an operation. Higher ISS, lower blood pressure, lower pH, and increased number of packed red blood cell transfusions were better indicators of the need for an operation versus embolization.