Abstract: The bioaccessibility of arsenic (As) in soils is governed by soil physiochemical properties, contamination sources, and testing parameters. In this study, As bioaccessibility was evaluated in 1 457 soil samples collected worldwide. The bioaccessible fractions of As ranged from 0.05% to 89.0% in the gastric phase and from 0.15% to 83.2% in the intestinal phase. The mean gastric-phase As bioaccessibility decreased in the order of: industrial (31.3%)>urban (24.3%)>agricultural (23.5%)>mining/smelting (19.9%)>tailings (13.8%), whereas in the intestinal-phase values followed the order of: industrial (24.6%)>agricultural (22.7%)>mining/smelting (18.5%)>tailings (10.5%)>urban (10.1%). Bioaccessible As concentrations were significantly and positively correlated with total As and organic matter contents (P<0.001), but significantly and negatively correlated with Fe, Mn, and Al contents (P<0.001). Among the methodological parameters, pH and gastric pepsin concentration exerted significant effects on As bioaccessibility, while extraction duration had a negligible influence. The 95th percentile As bioaccessibility values-56.9%, 59.3%, 69.7%, 30.2%, and 65.4% for soils derived from tailings, mining/smelting, industrial, urban, and agricultural sources, respectively are recommended as reference values for refined human health risk assessment.