The durability of alkali-activated slag (AAS) concrete exposed to acid attack was investigated. To study resistance of AAS concrete in acid environments, AAS concrete was immersed in an acetic acid solution of pH = 4. The main parameters studied were the evolution of compressive strength, products of degradation, and microstructural changes. It was found that AAS concrete of Grade 40 had a high resistance in acid environment, superior to the durability of OPC concrete of similar grade. 14 refs.