Sulphuric acid attack on concrete is a corrosive process that occurs when highly acidic substances come into contact with concrete structures. This attack has a number of adverse effects, including the dissolution of calcium hydroxide and the formation of less stable calcium sulfate and gypsum compounds, which can cause concrete surface erosion and cracking. Thus, this study focuses on the durability of fly ash geopolymer concrete (FAGC) under sulphuric acid exposure. The FAGC was cast using fly ash and a combination of sodium silicate and sodium hydroxide solutions. The hardened FAGC was then exposed to a sulphuric acid (H2SO4) solution for 6 and 12 months. The tests, such as a change in the concrete surface, mass, compressive strength, and X-ray diffraction (XRD), were conducted on the concrete specimens after the acid exposure, and the results were compared with Portland cement concrete (PCC). The result shows that the FAGC specimen did not deteriorate severely based on the visual inspection of the concrete surfaces. In addition, the FAGC specimens experience a lower mass loss and changes in compressive strength than the PCC specimen after the acid exposure. The microstructural analysis also proved that the FAGC structure did not change significantly compared to PCC, which experienced significant changes after the acid exposure. Thus, it can be concluded that the FAGC has higher resistance toward sulphuric acid than the PCC.