This study investigates the effect of steam curing on the early strength of mortars that include mineral admixtures. Instead of CEM I 42.5 R cement, 0, 10, 20 and 30% of fly ash or 0, 5, 10 and 15% of silica fume was used in the mortars. In the composition of the mortars, the fine aggregate/binder/water ratios were determined as, respectively, 3/1/0.5 by mass. 40/40/160-mm prismatic specimens were cast and divided into two groups. The first group of specimens was cured in water at 20 degrees C for 1, 2, 3 and 28 days. The second groups of specimens were exposed to 24-, 48- and 72-h curing at procedure temperatures of 35, 50, 65, 80 and 100 degrees C. Following the curing, compressive strength of mortar specimens was determined. In this study, the accelerating curing temperature and time for the early strength of the mortars containing fly ash/silica fume were tried to determine according to compressive strength test results.