Concrete prisms and cylinders were made using four different cementitious materials. These were high alumina cement (HAC), Type 10 Portland, Type 10 with 20% replaced with fly ash and Type 50 Portland Cement. Specimens were used for measurement of length change and estimation of compressive strength over a period of about 18 months exposure to fog-room conditions, room temperature Na₂SO₄ solution or 40°C water bath. None of the concrete samples made with the 3-types of Portland-based cementitious material showed distress due to sulfate attack. The concrete made with HAC and which had probably not undergone the conversion reaction also showed good resistance to sulfate attack but samples in which conversion had probably occurred cracked and disintegrated in the Na₂SO₄ solution.