Purpose: To analyze causes of acute nonvariceal gastrointestinal bleeding(GIB) with negative digital subtraction angiography(DSA) results.Materials and methods: The clinical and follow-up data of 133 patients-recruited between February 2008 and November 2016-with acute nonvariceal GIB and negative DSA results were included in this study. DSA results,diagnoses, and clinical outcomes were recorded.Results: The DSA results were negative in all 133 patients. Of the total, 55 patients(41.4%) chose to undergo surgery and 78(58.6%) opted for conservative treatment. Within 30 days, there was no significant difference in the rebleeding or mortality rates between the two groups(P <.05). Of all 133 patients, 76(57.1%) had upper GIB and 57(42.9%) had lower GIB;within 30 days, the rebleeding rate in the upper GIB group(44.7%, 34/76) was significantly higher than that in the lower GIB group(26.3%, 15/57). There was no significant statistical difference(P <.05) within 30 days in the mortality rates between the two groups.Among patients with upper GIB, 26(34.2%, 26/76) opted to undergo surgery and 50(65.8%, 50/76) chose conservative treatment;within 30 days, the rebleeding rate in the group that chose surgery(61.5%, 16/26) was higher than that in the conservative treatment group(36%, 18/50). There was no significant difference(P <.05)within 30 days in the mortality rate between the two groups.Among the patients with lower GIB, 29(50.9%, 29/57) chose to undergo surgery and 28(49.1%, 28/57) opted for conservative treatment. Within 30 days, the rebleeding rate in the surgery group(13.8%, 4/29) was lower than that in conservative treatment group(39.3%, 11/28). There was no significant difference(P <.05) within 30 days in the mortality rate between the two groups.Sixteen patients underwent prophylactic arterial embolization;in 6 of these, bleeding was stopped for 30 days.DSA was then repeated in these 16 patients after a median interval of 1 day, and a positive bleeding site was found in 9 of the 16. Causes of bleeding were found in