In this investigation, mortar samples with no pozzolanic material or with 5, 10, 15, 20% silica fume or 30, 50 and 70% ground granulated blast furnace slag were subjected to twice daily heat cycles between room temperature and 65 °C for 90 days. The effect of the heat cycles on moisture loss, compressive strength, ultrasonic pulse velocity and drying shrinkage was assessed. The inclusion of pozzolanic materials in the heat cycled mortars increased moisture loss and reduced the compressive strength in all but the 5 and 10% silica fume mortars. The ultrasonic pulse velocity was affected to various degrees, whereas the observed shrinkage values for pozzolanic mortars after exposure to heat cycles were excessive.